DIY Concrete Block Soaking Pool - In Progress, Advice Welcome!

[tribly]

Hello all!

First talked to you over a year ago as I was scheming on a possible little tiled concrete block soaking pool I wanted to build: http://www.troublefreepool.com/threads/82956-DIY-Concrete-Cinder-Block-Spa-Pool-Advice. You helped get me started (thanks!) so I thought I'd keep it going as I finally start on the project.

I'll use this thread to post my progress, ask questions, get advice, and be told I'm "doing it completely wrong"! Always happy to hear your advice or suggestions. So here we go!

The Plan (Very Simply)

• A 9' x 6' x 3' deep heated/filtered soaking pool (900 gallons about). Has a bench 18" high and deep running around the entire perimeter. 3, 1' deep steps on one side going down into pool. Mostly in ground, but 1' above grade too.
• Poured concrete floor/bench (w/rebar), concrete block walls (masoned in, vertical rebar, concrete filled)
• 1 skimmer, 2 main drains, 1 return, 1 small light, 1.5hp pump, 50sqft cartridge filter, 5.5 or 11kw electric heater (debating, hoping to maintain at least 100 degrees F, in Portland, OR so never gets too cold)
• Covered with waterproofing membrane (Laticrete 9235?), then titled (ceramic). Capped with a natural stone coping
• Ultimately going to be something like this or this

The Status
Digging, digging, digging (tip for those who have rocky clay soil like myself, wet dirt is 10x easier to dig than dry!). Only about a 1' left to go, then sort of the 'fine' digging where I straighten edges, even things out etc.

The Next Step
After finishing up the digging it'll be:

• 2" of crushed rock tamped down in bottom
• Lay rebar (#3) on 1x1' grid in bottom
• Put in main drain (planning on just 1 in the bottom, centered; putting a 2nd one in the wall later on) and plumb back to filter/pump area
• Run #8 bare copper bonding wire along rebar, leaving plenty of room to connect to light fixture, rebar in walls, pump/filter, and heater
• Pour concrete in floor (4" thick)

The Questions

1. Looks like if you have a main drain, you need to have 2 to avoid suction/entrapment stuff, correct? This is a little pool (the very bottom is only 4'6" x 3'4") so putting in 2 8" drains at least 3' apart seems like it's a) an unecessary amount of drainage for 900 gallon pool and b) will take up a lot of floor space if I put them both in the bottom of the pool. Thinking now is to do one, centered in the bottom, 1 along near the bottom of the sidewall. Question is, are there any alterative drain setups for a small spa/pool like this? Or is it perhaps just smart to just use the skimmer as th drain (goes back to the pump/filter)? Any other thoughts on this?
2. Plan right now is to have one of the main drains in the bench wall about 5" up from the bottom of the pool. The return would be on that same side, about 8" from the top of the water line (so roughly 20" higher than the main drain). Is having the return (pumping hot water out) and the main drain (pulling water back in) on the same wall inefficent? Meaning is the drain just going to be pulling out the hot water I pumped in and it won't be circulating well?
3. As mentioned, it's about 900gallons. Debating between 5.5kw and 11kw electric heater. 5.5kw are suggested for about 600gallons, but I could get a 'spa pack' meaning it includes a lot of the thins together (heater, light, controls) so less room for error on my part which is appealing. Seems like 5.5 would just heat up slower, but should be able to maintain 100 degrees just fine. Any insights?
4. Trying to figure out the light situation/niche. Debating between a fancy, proper Pentair SpaBrite (w/proper niche) or something smaller/simpler which I'd mount in a PVC pipe. Would the smaller one be bright enough in your opinion? Any experience installing a light into a PVC pipe niche (as opposed to a specifically made niche)?
5. Planning to dig a little box (covered eventually) right next to the pool to house the heater/filter/pump. Is that OK or are their restrictions on how close the electrical stuff can be to the pool? Would there be noise issues if it's so close (small heater/filter/pump so hoping not)?

Anyway, obviously I have way more detailed plans, but didn't want to bore you with all those. Let me know if you have any questions, see I'm doing anything wrong, or have any advice! Thanks all!

 

[JoyfulNoise]

The Questions

1. Looks like if you have a main drain, you need to have 2 to avoid suction/entrapment stuff, correct? This is a little pool (the very bottom is only 4'6" x 3'4") so putting in 2 8" drains at least 3' apart seems like it's a) an unecessary amount of drainage for 900 gallon pool and b) will take up a lot of floor space if I put them both in the bottom of the pool. Thinking now is to do one, centered in the bottom, 1 along near the bottom of the sidewall. Question is, are there any alterative drain setups for a small spa/pool like this? Or is it perhaps just smart to just use the skimmer as th drain (goes back to the pump/filter)? Any other thoughts on this?
2. Plan right now is to have one of the main drains in the bench wall about 5" up from the bottom of the pool. The return would be on that same side, about 8" from the top of the water line (so roughly 20" higher than the main drain). Is having the return (pumping hot water out) and the main drain (pulling water back in) on the same wall inefficent? Meaning is the drain just going to be pulling out the hot water I pumped in and it won't be circulating well?
3. As mentioned, it's about 900gallons. Debating between 5.5kw and 11kw electric heater. 5.5kw are suggested for about 600gallons, but I could get a 'spa pack' meaning it includes a lot of the thins together (heater, light, controls) so less room for error on my part which is appealing. Seems like 5.5 would just heat up slower, but should be able to maintain 100 degrees just fine. Any insights?
4. Trying to figure out the light situation/niche. Debating between a fancy, proper Pentair SpaBrite (w/proper niche) or something smaller/simpler which I'd mount in a PVC pipe. Would the smaller one be bright enough in your opinion? Any experience installing a light into a PVC pipe niche (as opposed to a specifically made niche)?
5. Planning to dig a little box (covered eventually) right next to the pool to house the heater/filter/pump. Is that OK or are their restrictions on how close the electrical stuff can be to the pool? Would there be noise issues if it's so close (small heater/filter/pump so hoping not)?

Anyway, obviously I have way more detailed plans, but didn't want to bore you with all those. Let me know if you have any questions, see I'm doing anything wrong, or have any advice! Thanks all!

Answers

1. Yes, you should have two MD's to avoid suction entrapment...HOWEVER, why don't you talk with user mas985. The truth is pools are built with MD's for historical reasons ONLY. They are, from a hydrodynamic perspective, utterly useless. There is a great video showing a test rig where there's a skimmer and an MD. The MD is operating at some insanely high flow rate, like >800gpm. The person drops blue dye over the MD which is only inches from the dye and most of dye simply floats past the MD. So, if you're willing to be different (and this thread is going to be VERY different), consider bagging the MD's. It will also make the setup and plumbing much easier.
2. See comment/answer above
3. Considering the size/volume of the pool and assuming cost is not a huge issue, I'd go with the larger heater. You always want to give yourself plenty of operating margin.
4. The Pentair niche is nice and will make it easy to change out lights of you need it. I have a 300W halogen light in my spa and it puts out a TON of light. If you go low-voltage LED, you can get all the colors you want and it will look really fabulous.
5. You can get some very quiet pumps nowadays. I would NOT bury equipment. Keep it above ground and just build a proper equipment pad with covers. Trying to service equipment in odd locations like that is just asking for trouble. Also, there are typically electrical code restrictions on how far away pool equipment must be from the water. You should try to follow code as much as you can.

That last answer brings me to a related point in my head - while I think your idea here is really cool, have you considered what you're doing in light of pool building codes which typically require city/county permits and approval? As well as homeowner's insurance implications?

I'm not trying to pee-on-your-parade, but I hope you realize that building something like this, without following proper local codes and permitting procedures, means that you are totally liable and completely responsible for any harm caused by this water feature. The example would be a child visits your home, falls in the pool and dies or a person sitting in your awesome pool gets electrocuted. In that case, without proper permitting and approvals, your homeowners insure would not cover you at all and you'd be criminally and civilly liable for all injury and damages. As well, if your local town or city ever got wind of this (say from a cranky neighbor), they could come in a declare that pool a hazard and force you to remove it at personal cost and with daily fines. And even on the most basic level, you could never sell your home with something like that in the ground. So even if nothing happens, you're on the hook for removing it if ever you want to sell.

Again, I'm not trying to be a wet-blanket and I love cool DIY stuff like this, but there are greater implications here and I hope you have contingency plans for them.

Good luck,
Matt

 

[pooldv]

Cool project!

There are some new channel drains available now that are 2 or 3 feet long that might work better. Agree that bottom drains do not have much suction, mine is no exception. But, it is convenient to turn all suction to the drain and brush the dirt/debris to the drain and not have to vacuum. If you brush the debris right to the drain it will suck it up.

Here is one channel drain option, AquaStar Pool Products - VGB Series Channel Drains

 

[tribly]

I'm not trying to pee-on-your-parade, but I hope you realize that building something like this, without following proper local codes and permitting procedures, means that you are totally liable and completely responsible for any harm caused by this water feature. The example would be a child visits your home, falls in the pool and dies or a person sitting in your awesome pool gets electrocuted. In that case, without proper permitting and approvals, your homeowners insure would not cover you at all and you'd be criminally and civilly liable for all injury and damages. As well, if your local town or city ever got wind of this (say from a cranky neighbor), they could come in a declare that pool a hazard and force you to remove it at personal cost and with daily fines. And even on the most basic level, you could never sell your home with something like that in the ground. So even if nothing happens, you're on the hook for removing it if ever you want to sell.

Thanks for the advice, Matt. Been going back and forth about whether to permit it or not. Definitely going to make it safe / largely to code, but there's a 4' fence requirement here that I really don't want to have to do. If I can make it only 24" deep, I can get around that so might consider that...maybe. Still pondering that all.

Yes, you should have two MD's to avoid suction entrapment...HOWEVER, why don't you talk with user mas985. The truth is pools are built with MD's for historical reasons ONLY. They are, from a hydrodynamic perspective, utterly useless. There is a great video showing a test rig where there's a skimmer and an MD. The MD is operating at some insanely high flow rate, like >800gpm. The person drops blue dye over the MD which is only inches from the dye and most of dye simply floats past the MD. So, if you're willing to be different (and this thread is going to be VERY different), consider bagging the MD's. It will also make the setup and plumbing much easier.

Yeah, really rethinking the main drains right now. Been reading a lot on the forum (this thread in particular). I think using either just the skimmer with a equalizer (something like this) or two 1.5" side wall suction drains. The latter seems like it'd be better for circulation (as far as I understand, the equalizer doesn't kick in unless water's below skimmer), but can't figure out what cover's I would need to put over the drains and if I should plumb it into the skimmer somehow.

But yeah, thanks for the tips. Very helpful all around! Going to finish digging today. I'll keep you all posted.

 

[JoyfulNoise]

tribly,

Totally understand your situation. Look forward to your build thread.

Is just go with a skimmer and equalizer setup. Given the size of the pool, I think your circulation will be adequate. I might suggest you add on a dedicated vacuum port so that you can run a small manual spa vacuum head without giving to use the skimmer for the hose attachment.

Good luck!!

Matt


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[tribly]

Finished digging! Had some rain so waiting for the ground to dry out a bit before tamping in the gravel.

Looking at skimmers / equalizer options. Thinking something like the Hayward SP1071 right now. HOWEVER, looks like the unit is 15-16" deep. Since the top 1' of my pool is out of ground, and my walls are only going to be about 1' thick (6" from concrete blocks, 6" from decorative stone veneer), this would stick out of the wall oddly. I'm sure I could find a creative way to work around that, but is it possible at all to plumb an equalizer line into a single hole spa skimmer (which is only 6" deep)? Or does anyone know of any smaller (less deep) 2 hole skimmers?

Also, bonding. Just to make sure I have it right I need to run the bare copper wire along the rebar, tying in a several places, and leave enough room to also tie it into to all the electronics (light, filter, pump, and heater), correct?

 

[JoyfulNoise]

Finished digging! Had some rain so waiting for the ground to dry out a bit before tamping in the gravel.

Looking at skimmers / equalizer options. Thinking something like the Hayward SP1071 right now. HOWEVER, looks like the unit is 15-16" deep. Since the top 1' of my pool is out of ground, and my walls are only going to be about 1' thick (6" from concrete blocks, 6" from decorative stone veneer), this would stick out of the wall oddly. I'm sure I could find a creative way to work around that, but is it possible at all to plumb an equalizer line into a single hole spa skimmer (which is only 6" deep)? Or does anyone know of any smaller (less deep) 2 hole skimmers?

Also, bonding. Just to make sure I have it right I need to run the bare copper wire along the rebar, tying in a several places, and leave enough room to also tie it into to all the electronics (light, filter, pump, and heater), correct?

Can't you make the skimmer flush with the pools interior surface and then just dig out more on the back end? I guess I need to see the hole in the ground and where you're placing the skimmer.

As for bonding, yes you want to use #6 bare solid copper conductor and attach it to several points on the rebar completing a circle around the pool. If you plan to have any concrete decking, you want to leave some wire to bond to any mesh or rebar used in the decking. Then that wire goes out to the equipment pad where you attach it to the outside motor casing and heater. Check with local code but it's often NOT necessary to attach the bonding wire to the electrical panel ground. The motor casing will be ground connected as well so the entire bonding loop will eventually be at ground once you're all hooked up.


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[tribly]

Making progress. Almost done with all the concrete work. Now starting to plan out the electrical (the thing I know least about). Here's what I have planned so far:

- Install a 70 amp breaker in my main electrical panel
- Run wire (#4) from main panel, outside, through buried 1/2" PVC conduit, to a sub-panel near the pool
- Sub-panel will be 4 space (8 circuit), 125 amp max
- I'll install a 30amp, 240volt, 2-pole GFCI circuit in the sub-panel and wire the 5.5kw (about 22 amps) heater into that (4 wires, neutral, 2 hot, ground)
- I'll install a 20amp, 120volt, 1-pole GFCI circuit into the sub-panel and run that to an outlet where I'll plug in the 1hp filter/pump (10 amps or so) and a small, fountain pump (can't imagine it'll be more than a few amps)
- Bonding wire will be tied into the heater, filter/pump, and (optionally) the sub-panel

Leaves me 1 space in the sub-panel in case I need anything else in future (which would be nice).

Some questions though:
1. Does any of that make sense. Overkill? Not enough?
2. Goal is 70 amp sub-panel. I'll have at least 2 GFCI circuits installed. When looking for circuits to install in the main panel and run out to the sub-panel, largest GFCI circuit I see for sale is 60 amps. Do I need a GFCI circuit to connect the main panel to the sub-panel? Or will the sub-panel have it's own grounding so GFCI happens there?
3. This points to my limited electrical knowledge, but I see some (very cheap) spa-specific sub-panels with just 2 slots (for 1, 2-pole 50amp breaker, example: Eaton 50 Amp BR Type Spa Panel-BR50SPA - The Home Depot). 50 amps might be enough or me, but I imagine there's not a real good way to split it into a hard wired 30 amps at 240 volts for the heater and 20 amps for a 120 volt outlet, is there?
4. Again, shows my limited knowledge, but I see that the 2-pole circuits are listed as 120/240volt. So what exactly determines if a device (outlet, hard wired heater, etc) will use the 120 volts or 240 volts?

Slowly figuring out this electrical stuff, but may need to hire (or at least talk to) an electrician in the end. Hoping you guys can illuminate things for me a bit though!

Anyway, some progress pics!

All dug!

Form, gravel, rebar, bonding wire (not the prettiest)

Learning how to pour concrete...worrying I've done it all wrong

Not too shabby for a first time

First level of blocks laid. Had a bit of rain. HELD WATER!!! Even before the waterproofing. Good sign.

Backfill and plumbing for light and equalizer (light I'm using fits in a 1.5" pipe)

Bench form, gravel, rebar, and some more bonding wire just because

That moment when you realize you don't have enough concrete mix for your pour...

Quick trip to the store and the bench is finished off

Today's work. Did about half the exterior wall blocks.

Anyway, surprised at how well everything's going so far! Thank you all for helping me out!

 

[JoyfulNoise]

Wow!! Nice concrete work.

I'll leave the electrical answers to the folks on TFP that are experts but I did have one question - why a 120V pool pump and not a 240V pump? I could be totally wrong, but I thought 240V would be more efficient in your setup as they draw less current than a 120V pump.


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[gwegan]

You should probably hire an electrician. Your post exposes some basic errors.

First ----- did you put bonding wire in your pool shell? Bare copper 8 gauge connected to the rebar by a listed clamp and emerging from the shell at four distinct locations?

1. I suspect a 70 amp breaker is overkill. I believe you need a 50 amp double pole breaker at your main panel for your subpanel. Your heater calls for a double pole breaker so we have to start with a double pole breaker and two hots from the main panel. I can't be sure of any of the sizing here because I don't know the specs for your pump or heater. Tell me the heater make and model and I can be more specific.

2. I suspect 4 gauge wire is overkill. But I need to know about your heater.

3. 1/2 inch conduit is too small. Min 3/4. You need to fit two hots (prob 8 gauge) a neutral and a ground in there. What are the specs for your heater and pump and what is the distance from the main to the sub? That will determine breaker size and wire size.

4. Separate double pole breakers in the sub panel one for the pump (get a 220 pump) and one for the heater. Size per pump and heater mfg instructions. An additional 20 amp circuit for everything else.

5. You need a outlet (plug) between 6 and 20 feet from the pool. It can be on your equipment pad or hanging from the subpanel or it can be on the back wall of the house.

6. You don't bond the subpanel.

7. I think a 1 hp pump is too much. I suspect a 1/2 or 3/4 hp pump will do just fine. How much water are we moving? We eliminated the drains because tis is a soker tub right? So we are not moving a lot of water.

8. You should be looking at custom portable spa covers.

Those are my initial thoughts. Post info on your heater and pump and I can be of more assistance. But consider an electrician.

 

[dw9000]

Looks good, concrete looks good and block work looks good. Just keep a level handy and make sure they are perpendicular to the floor. Use a string line to make sure the wall is straight. Looks like a fun project.

 

[tribly]

Thanks for the tips, gwegan. Responses below.

First ----- did you put bonding wire in your pool shell? Bare copper 8 gauge connected to the rebar by a listed clamp and emerging from the shell at four distinct locations?

Yep, I put bonding wire in the shell. 50' feet of it making a complete loop on both horizontal levels, tied into the rebar at 8 places. It only emerges from the shell at 1 place though which will go to the heater/pump to be tied in there too.

1. I suspect a 70 amp breaker is overkill. I believe you need a 50 amp double pole breaker at your main panel for your subpanel. Your heater calls for a double pole breaker so we have to start with a double pole breaker and two hots from the main panel. I can't be sure of any of the sizing here because I don't know the specs for your pump or heater. Tell me the heater make and model and I can be more specific.

2. I suspect 4 gauge wire is overkill. But I need to know about your heater.

Cool. Just wanted to make sure I wouldn't be tripping anything with the heater, pump, and a smaller fountain pump all on the same breaker. You suggested 2 double pole breakers below (1 for the heater, 1 for the pump). Imagine those would be 30amp each (maybe 15 or 20 amp for the pump). That, plus the 20amp adds up to at least 65 total amps (or 80 if I use a 30 amp double pole for the pump). I know 50amp subpanel means it'll handle max of 50amp being pulled, and the 3 breakers won't always be pulling their max, but is having 80amp breakers on a 50amp max subpanel ok?

Also, specs for the heater:
Balboa VS500Z Spa Control System Complete 54219-Z. Balboa 54219-Z

And filter/pump combo:
Waterway Plastics | Waterway 50sqft Cartridge Filter System with 1.0hp Pump | Discount Pool Kits

As you'll see, the filter/pump is 115volts, plugs into a GFCI outlet. Was hoping to just have a 115volt outlet wired to a 20amp GFCI breaker and be able to plug the pump in there. Would there be something wrong with that setup?

3. 1/2 inch conduit is too small. Min 3/4. You need to fit two hots (prob 8 gauge) a neutral and a ground in there. What are the specs for your heater and pump and what is the distance from the main to the sub? That will determine breaker size and wire size.

Was wondering if 1/2 would be too small. 3/4 in should be no problem. See above for heater/pump specs. Distance between main panel and sub panel will be approximately 70 feet.

4. Separate double pole breakers in the sub panel one for the pump (get a 220 pump) and one for the heater. Size per pump and heater mfg instructions. An additional 20 amp circuit for everything else.

Already bought a 115 pump/filter combo so hoping that will work (see above). 1hp is probably overkill, but wanted to make sure it could filter out the water pretty easily. Should be about 960 gallons of water. And your correct, no main drains. Just a skimmer with an equalizer.

5. You need a outlet (plug) between 6 and 20 feet from the pool. It can be on your equipment pad or hanging from the subpanel or it can be on the back wall of the house.

Good to know. What's the purpose of the outlet? I know I should have a...I guess kill switch you'd call it, not too far from the pool so I could shut if all off if needs be (that's the subpanel I presume). Is the outlet something to do with that or something else?

8. You should be looking at custom portable spa covers.

Already on it, but thanks for the tip!

And yeah, thanks for all the advice. Definitely open to getting an electrician. But want to make sure I understand the stuff too. So thanks again for your help!

 

[JoyfulNoise]

I see a problem - the link to your combo pump/filter shows an above-ground pool pump. You technically have an in-ground pool. The difference between the two is important because ABG pumps are typically NOT self-priming. If your equipment pad sits above the water level, you'll never be able to prime the pump on startup. You need an in-ground pump which is self-priming.

Maybe they make a similar combo unit for an in-ground?


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[gwegan]

I went looking for but couldn't find manufactures spec sheets for the pump and the heater. I prefer to see the plate on the pump and heater with the electrical specs or a spec sheet. To answer your questions we need those. The big question is how much does the heater and pump draw. That will determine wire size and breaker size. The distance from the main panel to the subpanel is 70 feet?

Your bonding doesn't comply with code but should be OK. What are you putting around the pool? Pavers? Poured concrete? Those should be bonded with some grid underneath.

You may be ok with your above ground pump --- just make sure its at least a foot below the bottom of the skimmer. 1 hp pump to move 980 gallons? Thats going to be a fast turnover.

I think you are going to have to construct some type of weather enclosure for your heater. It looks like its meant to be installed inside a cabinet or something. Check the installation requirements.

Its difficult to know if you are a spa or a pool.

You should have separate outlets for your pump and your utility plug, generally they are on different circuits.

Suggestion:

Go Here: Mike Holt Free Mike Holt Publications and Industry Manuals and download the Swimming Pool publication -- its free Read it like six times.

 

[tribly]

I went looking for but couldn't find manufactures spec sheets for the pump and the heater. I prefer to see the plate on the pump and heater with the electrical specs or a spec sheet. To answer your questions we need those. The big question is how much does the heater and pump draw. That will determine wire size and breaker size. The distance from the main panel to the subpanel is 70 feet?

Hope these are what you're looking for.

Heater

Pump/filter

Also, maybe closer to 60 feet from main panel to sub. Main is in basement, on the other side of the house so I'll have to run wire through basement rafters (40' or so) and sub-panel will be nearish to pool which is 20' or so from back of house.

What are you putting around the pool? Pavers? Poured concrete? Those should be bonded with some grid underneath.

Exterior wall goes about 1' above grade with irregular stone pavers on the ground around it (something like this: Plunge Pool - Traditional - Pool - boston - by Woodburn & Company Landscape Architecture, LLC). Do I need bonding under the pavers in this case you think?

You may be ok with your above ground pump --- just make sure its at least a foot below the bottom of the skimmer.

Good to hear (can't believe I missed that it was an above ground pump). Already going to be about a 1' beneath (since exterior walls are 1' above grade), but I'll put my pad down a little below grade anyway just to be safe. Thanks for the tip.

And yeah, the pad (heater, pump) will be enclosed in a box/cabinet. And good to know about having separate outlet/circuit for pump and utility plug. Should be doable.

And read through the applicable parts of the manual you mentioned. Dense, but full of good info. Thanks for that. I'll keep reading through and keep it on hand for reference.

So I guess now I just need to figure out sub size, wire size, and circuit sizes. And make sure the distances between everything are alright.

Thanks again for all your help!

 

[tribly]

It's been ages since I posted last. Mostly because I've been soaking in my pool and too lazy to do anything else! Not finished yet (still need to do the tiling, waiting for summer, and the exterior rock) so it looks pretty ghetto, but thought I'd share some thoughts on the process in case it helps anyone else.

First, a photo or two:

Now, I was completely oblivious to how this all worked when I started and I made some dumb assumptions / mistakes. So here are some things I've learned (that I wish I knew earlier). Might be obvious to most of you, but thought I'd share anyway.

Energy Cost
When I looked into this previously, seems like people spent $25-$30 a month heating their hot tub. My first electric bill was $365 higher than normal . Granted it was January (real cold) and I had get it from 45 degrees to 100, then had to partially drain it, fix some leaks, re-fill, reheat...then did that again. But when I saw that first bill I immediately googled way to optimize hot tub energy.

When I ran numbers, figured out that heating was about 80% of the cost (as opposed to pump, SWG, light, etc.) so needed to tackle that:

* Insulate, insulate, insulate!!! Didn't put any insulation around the concrete when I poured it (besides dirt) and apparently it's not a great insulator. Found this engineers blog on insulating his own pool: Ambivalent Engineer: Insulating the pool Super helpful info (I wish I had known earlier). At any rate, I still hadn't filled in dirt around the whole thing so managed to get some insulation (the R-Tech stuff they put on the exterior of houses) around the top half of the shell (photos below).
* Also insulated all the pipes with Reflectix roll insulation (the stuff they put in coolers). Not sure how much it helped, but I'm sure it was worth the cost.
* I had built a DIY hot tub cover for about $100 which was nice (it rolled on and off real easy), but when I got that first bill I immediately ordered a proper cover. Since my tub was pretty big (8' 10" x 6' 2" on the interior) I had to get a custom, large one (which was pretty spendy at $650). Not sure it saved me as much as it cost (see calculations below) and it's a hassle to get on/off, so probably will just try to improve my DIY one and make it look prettier when the custom one wears out.
* A floating thermal blanket is like $30 and definitley saves you that much (both in terms of heating cost as well as reducing evaporation or water / chemicals).

Next step was to try and improve the pump / flow rate. Had a 1 HP pump to start with which was basically like a hot tub jet in my single return (kind of nice), but was way too much so got a 1/8 hp circulation pump. Played around with having both of them plumbed in (the 1 HP was wired to the 'Jet' button on the pool), but in the end it was too powerful for a jet and not worth the reduction in flow / feet of head it caused having it plumbed in.

Anyway, my original plumbing was real janky (had lots of 90 degree turns, had two 6' pieces of corrugated, flexible hose pipe that was literaly just running in circles) so needed to fix that so the 1/8 hp pump would meet the reuired 25 GPM my hot tub heater required. Here are my thoughts on that:

* As far as I understand it, getting the pump to flow water faster makes the heater heat the pool faster (aka, cheaper). There are, of course, cost / benefit analysis based on increasing pump size / HP, but keeping the same pump and improving flow is all gain, so...
* Make sure you consider feet of head and efficent flow rate.
* Use 'sweep' elbows where you can (12% more efficent according to this: Do Different PVC Fittings Really Make a Difference in Water Flow? - POND Trade Magazine)
* Reduce number of elbows
* A reduction down to a smaller pipe size, even for just an inch, real reduces flow (I think one of my main problems was I had 1" ends on my flex hose). Keep it all the same size (in my case 1.5").
* Side discharge pumps are more efficent than center discharge (obvious to most of you, but new to me)
* Having a clear, straight shot before the pump is helpful (originall had an elbow just before it, no good).

Nerded out a bit as I implemented my changes to try and cut down on energy costs. Tracked my electric meter daily, came up with an equation to calculate monthly cost of the soaking pool, taking into account temp and hours used even. Anyway, here's what I found.

$150 - When I started tracking costs, this was the calculated cost per month of the soaking pool. This was before all the changes you'll see below.
$132 - After adding the professionally built cover (as opposed to my DIY one). Only $18 / month. Probably less after other improvements. Not sure it's worth $650.
$120 - Average after swapping out my 1 HP pump for a 1/8 HP pump. Still had the 1 HP plumbed in as a 'Jet'. Wasn't used much, but being in the plumbing reduced flow.
$108 - Average after removing 2 elbows after the heater, before returning to the pool. Drop ($12) seems big for such a small change so not sure it's accurate, but definitley helped.
$123 - My 1/8 hp circ pump stopped working (found a pebble had got lodged in it later, easy fix) so switched the 1 HP pump back to main pump. Plumbing was same otherwise. Jump of $15.
$103 - Fixed 1/8 hp circ pump, removed 1 hp pump from plumbing entirely, replaced 2 90 degree elbows with sweeps, cleaned up 1 or two other things in plumbing flow. Not a super accurate number as I ended up doing the next change before I could average out 4 or 5 readings for this, but just an idea.
$82 - Average after I put insulation around the pipes and finally back filled the pool with dirt (about 1/3 of the outer walls were exposed before this).

So, $82 / month isn't awesome when your'e expecting $30-40, but defintley better thanthe $365 I initially had so I'll take it. Tiles and landscape rock wall on exterior (still in the works) will help a bit too I'm sure.

Chemicals are No Fun
Was real naive about how many chemicals a hot tub needed. Assumed it was a little guy with a big filter (50sqft). That should be enough, right? Definitley not.

When it started smelling like pickles 3 or 4 days in, dove into the world of chemicals. There's already really good stuff here about all that in the pool school (Pool School - Pool Chemistry) and I'm still by no means an expert so I won't pretend. Got a bunch of chemicals and a test kit. Got things good, then checked it daily. Then got real sick of that.

Long story short, SWG to the rescue.

Went with the Chlormaker DO (drape over). So far so good. My tub is large enough that I have to keep it on full power all the time and it doesn't 'quite' keep up with recommended FC levels, but it's crystal clear and I don't really have to do anything (check levels of everything every month or so and adjust as necessary).

I did have too high a salt level at some point and it left a sort of burn/rust mark on the wall of the pool, but haven't tiled yet so no big deal. And hasn't happened since.

Hot Tub Heater / Control
Love my Balboa heater / control. Was easy to wire in circ pump and light, even had a jet pump wired in for a bit. But took me a while to figure things out too.

* If you're doing a weird, custom built thing like mine and you know next to nothing, buy a pre-built system. I tried to find one before, but failed. Have since found some at Spa Guts which would have been great: Spa Packs for Hot Tubs - A Replacement Pack for Spas. As it is, I spent a long time reworking plumbing to fit the pump in, swapping out pumps, wiring in new pumps, switching voltage on the balboa control board, and otherwise feeling dumb.
* It's possible to switch different ports on the balboa heater between 115v and 230v, just have to move some wires: http://www.balboawatergroup.com/getdoc.cfm?id=2081
* You can pretty easily wire your pump into a hot tub heater / control. Didn't realize before (was just gonna run it 24/7 on it's own, which would have been stupid). Real obvious in retrospect, but didn't realize it until I started installing things. Would have saved me a bit as I wouldn't have had to run such big wire or have such a big sub-panel (could have done 50amps or even 30amps, and didn't need an outlet).

Miscellanous Things
* Standard hot tub covers don't exceed 8' in either width or length. Mine was 9' long which meant a custom, large one and more than double the cost ($650 vs $300 for regular ones).
* Already mentioned, but 1hp is way more than you need for a 900 gallon hot tub (as someone else had mentioned). Ended up switching out for a 1/8 hp which was fine.

Anyway, I'm sure I have more things to share, but just a few thoughts for now.

Here are some more photos:

About to fill exterior wall cement blocks. Built form for top bit as another row of cement blocks felt just a little too tall. Building forms is tedious.

Concrete poured! Forms holding.

Messy yard.

Not too shabby

Hydro Ban water proofing membrane applied!

And dry!

Rainy Pacific Northwest makes things no fun. But it's holding water.

Not pictured, lots of:
- Fixing leaks - exculsively around the pipes / skimmer. Just had to put in some marine putty around them. Fixed it.
- Running / installing electrical - went very smoothly actually, easiest part. And no shocks!
- Installing pumps/final plumbing.
- Testing, finding leaks, fixing. Testing, finding leaks, fixing. Trying out cheap pump, failing, fixing.

But, on Christmas morning (literally), after 2 weeks of fiddling with everything, I finally woke up to a functioning, warm soaking pool!!!!

I had photos of drinking champagne on Christmas Day in there, but two days later walked into the pool with my phone still in my pocket so those are lost. But a few days alter.
Pictured you see the rolled up cover. Also, my janky system for protecting the heater / pumps before I finished off the box: a tarp.

When it snows, we drink champagne and laugh and the cold, cold world!

Here you see the DIY cover a bit more. Also R-tech insulation on the sides.

Afternoon charcuterie in the pool is a common occurence.

The floating thermal blanket. Also, finished box for pump/heater area. Also, installed a marine stero system (you can see speakers in bottom of the fence).

Proper (read, expensive) cover. Also, my original idea for a cover (4 sections of wood platform with insulation below) serving as a walkway to the pool as it was too heavy/cumbersome to take off / put back on.

And that's it! I'll update you when I have it tiled / the rock on the exterior (June-ish I think). Now off to enjoy happy hour in the warm waters of the very white trash, very difficult, somewhat expensive, but ultimately amazing and smile-inducing my own soaking pool!

 

[JoyfulNoise]

Great build thread!! Look forward to the updates. I'm a total foodie so any more pictures of your cutting boards full of cold meats and cheese are always a welcome site (feel free to share your favorite pool-side meals, with recipes!!, in The Coffee Bar sub forum).


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[kimkats]

What an adventure you have been on! With that wonderful write up someone else will be way ahead of the game!

Kim

 

[Jason B]

Great build thread!! Look forward to the updates. I'm a total foodie so any more pictures of your cutting boards full of cold meats and cheese are always a welcome site (feel free to share your favorite pool-side meals, with recipes!!, in The Coffee Bar sub forum).

Very cool. How about a new update???

 

[blay127]

no diving board?