Swim Spa, Unique Setup, Questions

[rob.mwpropane]

Hey everyone! I'm a little excited to share this as we bought the swim spa used from CL 2 years ago, and I'm finally able to say we spent our first few nights in it. It's so great I'm regretting not setting it up sooner! I've attached a link with some pictures for everyone's enjoyment;

1st Night

Spa is (not sure what brand....Haykeye I think, but they went out of business) 1800 gallons.

Now on to the technical stuff. I have this plumbed in to the same filter for the pool. I did this so I could disconnect the spa heater (5.5KW of electricity is too rich for my blood). This works flawless and the gas heater (400K Sta Rite) heated it from 65F to 99F in less than an hour! I have this tied in underneath so it does not effect the spa functions in any way. (2" "T" for supply, checkvalve, then "T" for return, all plumbed into a dual 2.5" drain under spa) I ran these lines up through an access I built into the slab before I poured concrete.

My question is this. I currently have a SWG and SW pool. I took water from the pool and dumped it into the spa (via valves at the pool pad).

Pool Pad (link);
Dropbox - Today

I don't think the low amount of salt (3000~3200ppm) will effect anything? Now I'm not entirely sure what to do about the chemistry. I've read the sticky at the top of this page, but wanted some suggestions from people with more experience. I really can't see using the SWG as a way to sanitize / chlorinate? I think it would add to much. Do most folks just test for the amount of sanitation needed and add bleach at the end of a soak? Another thing is my CYA is high for a hot tub (70 because of the pool), should I lower this to 30? (That would mean replacing with ~ 1026 gallons of fresh water!?!?!) I would really like to manage this with CYA of 70 if possible, because when it's time to do a water change, I'll just trade it out with the pool (No need to waste water).


Fwiw, some day I hope to have all this tuned with a Pentair Easy Touch, in which case I know I can set the "spa mode" to produce a much lower % of chlorine as per the SWG, which it would only produce when I turned it to "spa mode", ie when we're getting in or about to.

To sum it up;

1.) Is salt @ 3000ppm ok (I think so, and I've had no issues so far in a pool that was fresh water only)
2.) Can I manage it @ CYA 70
3.) Just test until I get a feel for how much bleach to add at the end of a soak and add it at the end of every soak?

Thanks all!

 

[ant 83]

CYA @ 70 is fine. Just follow the the CYA/FC chart.

Salt @ 3000 is fine as well, but be aware that it will go higher over time.

For every 10 ppm FC added by ANY source of chlorine, there will be 8.2 ppm salt from when the chlorine gets used/consumed and converts to chloride. For bleach, chlorinating liquid, and lithium hypochlorite, there is an additional 8.2 ppm salt added upon addition so the net result is 16.5 ppm salt from these sources

If it were me, I'd wait about 5-7 weeks, then replace a third of the water to reduce salt levels to minimize corrosion. Make sure to test cya levels to recalibrate FC targets.

Ideally, you'd test and add bleach every day. 60 hours is about the time limit on my tub for chlorine neglect. After long soak sessions or multiple people, I go back after a few hours and aerate and shock again, due to chlorine "debt" owed to the water from bather waste. If the pool is not heated all the time, chlorine loss is slowed down quite a bit.

Heating the spa with gas is a brilliant modification.

Is this spa covered?

 

[rob.mwpropane]

Heating the spa with gas is a brilliant modification.

Is this spa covered?

The gas conversion works amazing. I thought the spa might get a little "weird" with the heating element not connected, but so far all is good. I have wires ran from the spa to the control panel at the pad, with the idea that I'll tie into the heater at some point so the spa control can actually control the heater, and not just monitor temp. I have it all figured out how to do (for really cheap actually ~ $40?), just need to find the time to do it.

Thanks for the reply. It is covered (forgot to mention that), but the cover is on it's way out (generic, fold in half cover x 2 for the length). I know it'll have to do for this winter season, but next year I'll be looking into something more efficient / easier. I love the "End 2 End" cover, but that would cost more than my entire current setup!


Edit: Is there any possibility I can use my current SWG and maybe just run it while we're in the tub? This (as far as I know) wouldn't add any salt as adding bleach would. I can do the math to calculate how much I need to run the SWG for how long we were in for / how many people, etc., then just test periodically?

Example I know my Intex SWG is supposed to put out 11 grams/hour. I could setup a timer that I would set at the end of every soak to account for the amount of chlorine needed and then stop?

 

[ant 83]

I would, and I don't see any reason not to. You'll have to keep a close watch on PH, but I assume you know that already.

So nice that it's plumbed in already.

Do you have a plan for winter freezing temps? Don't you have to remove the salt cell then?

 

[rob.mwpropane]

I would, and I don't see any reason not to. You'll have to keep a close watch on PH, but I assume you know that already.

So nice that it's plumbed in already.

Do you have a plan for winter freezing temps? Don't you have to remove the salt cell then?

I'll have to post pictures of everything if anyone wants to follow.

I have removed the cell every year so far, but I'm not 100% sure it "needs" to be removed. My ultimate goal is to build an enclosure around the equipment. My experience is everywhere I go it seems sun and rain / being wet is what destroys any / all equipment. I have everything up against the house on a 9' x 4' concrete slab, so it wouldn't be too hard.

 

[ant 83]

It is my understanding the swg's have a temp sensor that shuts them off below 60.

I guess some have "winter mode" that runs at 20%. I don't know if it's just 20% of the time, or what.

In any case, you'll have to keep pipes from freezing. Are you going to circulate through the filter and heater non stop when it's cold out?

 

[rob.mwpropane]

It is my understanding the swg's have a temp sensor that shuts them off below 60.

I guess some have "winter mode" that runs at 20%. I don't know if it's just 20% of the time, or what.

In any case, you'll have to keep pipes from freezing. Are you going to circulate through the filter and heater non stop when it's cold out?

I'm not sure about the sensor and shutting off. If so, then I'm back to using bleach, lol.

Most of my pipes are underground (4'+ except for whats @ the pad itself). I have a VS pool pump that I plan to run (24/7) during the winter. Fingers cross it'll manage. I have a pretty decent cover over it. Again, at some point I hope to build an enclosure around everything to further protect it.

 

[rob.mwpropane]

Here's pictures of the plumbing;
Dropbox - Plumbing

 

[ant 83]

I've wondered how hard it would be to build a diy insulated cover. I was thinking of wrapping foam insulation with EPDM and sealing it water tight, then gluing on bathroom wall board so it looks presentable. The foam would be two thick with overlapping parts of the cover so pieces aren't too heavy to take off.

I've not been happy with my cover I have now. It's waterlogged, and replacement prices look insane to me.

 

[rob.mwpropane]

I've wondered how hard it would be to build a diy insulated cover. I was thinking of wrapping foam insulation with EPDM and sealing it water tight, then gluing on bathroom wall board so it looks presentable. The foam would be two thick with overlapping parts of the cover so pieces aren't too heavy to take off.

I've not been happy with my cover I have now. It's waterlogged, and replacement prices look insane to me.

I agree about covers, prices are ridiculous. Every quote I got was $2500USD+ (given, all really nice covers) I would love to build a DIY cover, I'm just not sure I have that kind of time. My cover is on it's last legs, one side is taking on some water, and the top is becoming wrinkled.

The EPDM is a nice idea. How would you make the sides / seems look nice? I'm thinking having a vapor barrier (like the blue bubble wrap solar cover) on top of the water would help some too. At least it would prevent excess evaporation.

Edit: just read you'd cover it in bathroom board, so the seems wouldn't matter

 

[rob.mwpropane]

Just an update;

Apparently, I'm not so good with the sanitation of a hot tub....which is amazing seeing as how (for the most part) the pool has been crystal clear for a few years now. I always get compliments on the water, and always give TFP credit.

With that said, my spa skills kind of suck. I can get the water to look "ok", but still not be what I know it can be.

For anyone that's read any of the above thread, my plan was to use the SWG that's tied in at the pad for sanitation. This worked wonderful except for the fact that it draws too much heat from the tub. A usual day will lower ~ 3-4F if I let it sit (No water ran to pad from spa). ( I use the pool heater to heat it, so 5 min and it's back where I want it ). If I use the SWG, the temp will drop closer to ~ 10F over a day, so the SWG is out of the question considering it hasn't really even gotten cold here yet.

So back to bleach. The issue is, now the water has more of a "chemical smell" with it. I have some MPS that I used once, and within a short time it seemed to get rid of that smell? Not really sure, and I hate using something I don't have a test for.

My thought process now is maybe lower CYA (30?) and again proceed with bleach? This would also help lower salt content as so no corrosion would occur (as stated above in another post).

I'm just throwing ideas out to see if something sticks before I make a move. Thanks.

 

[ant 83]

A couple of "hacks" I use for bleach smell reduction:

1: raise PH. Below about 7.3, "indoor pool" smells are a lot more noticeable.

2. Shock and aerate before use. Like a few hours ahead of time. Uncover, shock, aerate 15 min. wait two hours, repeat.

3. Don't let people see you add chlorine. EVERYONE smells it if they see you add it. It don't matter how much you add, or how much is there already.

 

[rob.mwpropane]

Ok guys, just a quick update and some more questions. First off, spa worked great with everyone's recommendations, so thank you to all that posted. Water chem was spot on for the rest of the season.

I have a bit of a dilemma that I didn't think about when I was building this setup. I have a ~ 1800 gallon swim spa that is heated from a gas heater which is ~ 35' away on a pad with the rest of my pool equipment. The issue I was having is that while the swim spa would keep temp pretty well, with the water circulating to the pad would draw too much heat away. I alleviated this during the fall by turning the pump off so no loss. Now that our temps have consistently been below freezing in Maryland I've had to leave the pump on. I had it set to 700 rpm's, but that didn't move the water fast enough to not freeze. It was a pain, but I was able to disconnect everything and move it to the basement to thaw. Thank goodness nothing was damaged. I put everything back together, heated it to 100F and ran the pump (so as to not freeze) @ 1000 rpms. Well in about 12 hours my spa went from 100F down to 80F (obviously heater is off). It became a game of cat and mouse, circulating enough water to not freeze, but keeping the flow as low as possible to not draw too much heat out. Yesterday I said the heck with it and winterized it and brought all the equipment in. I really like having the spa, and would like to be as energy efficient as possible. Here's some 2 options that I've come up with;

1.) I can insulate spa pipes that are underground and build an enclosure around my equipment. This would cost more than option 2, but that's why I'm here to figure what's best. The enclosure would essentially be an addition to the house and the air would be conditioned just as the house. Not as much heat loss and could run the pump super slow because no worry of freezing.

2.) I can reconfigure the lines and install the equipment in the basement. (Walk out basement, so pool water line would still be below but spa water line would be above). This option would be cheaper because I just need to re-run about 10' pipe underground. I know there's the issue of a catastrophic failure the spa water ends up in the basement, but I think I could add a drain that could handle that. The other issue that I can see would be the heater. I'm ok running intake and exhaust outside, but how much heat will it add into the basement? It's a pentair 399K system. In the winter I'm ok with the added heat, but in the summer I could see it being an issue. I can insulate the exhaust to avoid a lot of that, and I know the heat exchanger itself in the unit is insulated. I have a gas tankless water heater on the same wall, while not exactly the same it doesn't add any heat whatsoever to the basement (intake / exhaust are both ran outside). The Rheem pool heaters seem to tend to put off a lot more ambient heat than the pentair units. The pentair units are all insulated and plastic for the most part except for the exchanger / exaust. I could always add more insulation if this was an issue.

I'm just bouncing around ideas. I really want to avoid running the electric heater in the spa. Keeping that much water heated with electric 24/7 scares me. Since the install, I've had the electric heater wires disconnected and have only used gas. It was started on 9/23 and I've only used about $95 to heat it since then (even with the heat loss from the circulation to the pad). I only use the heater on nights when we know we're getting in (Which was quite a lot in the fall for sure, lately not so much. No fun when your face feels like it's falling off with 15F wind chill). Takes about 30 / 60 min to get up to temp depending where start temp is. I turn it on before dinner and it's ready to go when we are.

 

[rob.mwpropane]

Still looking to get anyone's ideas on this? Not something I'm doing soon, but still. Thanks.