Hydraulic Configuration for 2 Pool plus Spa Setup

[Kennerb4]

Okay, a newbie here and somewhat new to a forum setting so please bear with me. I have a situation that is a head scratcher for me but perhaps not for an experienced contractor or Hydraulic Engineer. I admit this is a very unusual setup and would not be my design if I had started this project from scratch so I do expect to get razzed a bit from this otherwise “professional, trades based, and experienced owner forum” at TFP but here goes.

Our house is located in a rural area of mid Missouri, so my pool resources are somewhat limited. I currently have a 12 x 24 Kayak, on ground, pool that was already installed when we purchased this country setting home a few years ago. Our rather large extended family and friends necessitated a larger pool. Not thinking about the details back then, my quick fix was to purchase an additional 16 x 32ft Kayak pool to install next to the original 12 x 24ft pool. I installed the new 16 x 32ft. pool so that the two pools are in an L shaped configuration along with new composite decking between and around them. To add to the mix, we have a rather large, in ground (in deck) kidney shaped, fiberglass, spa that's about 10ft x 7ft x 4ft deep (inside dimensions). It is also part of this whole pool setup.

I'm now looking for the best hydraulic configuration to maintain these three bodies of water. Currently, only the 12 x 24ft. pool is plumbed and filled with water. The spa and the other pool are set up and ready to connect up the plumbing. My plan is to purchase a new 250,000 BTU (or larger) propane heater for the hot tub, with the option to take the chill off the other two pools if they are colder than about 82 degrees. I also hope to use automation (at least for the hot tub) so that I could remotely heat up the hot tub from my phone, before we drive to this property on the weekends. With that in mind, the new Hayward Tristar VS 900 Omni 2HP pump with automation sounds interesting to me but I’m open.

I realize that I should have removed the existing Kayak pool and had a larger, in ground, pool put in its place when we purchased this home two years ago. At the time, it just seemed like such a waste of money since Kayak pools are not inexpensive and it was very new when we purchased this house.

I’m now at a loss on how this should all be plumbed so that I am not maintaining three bodies of water along with the work and expense of running three separate pumps and filters (not to mention the steps involved to winterize the entire system). Should I put the hot tub filter, pump, and blower on a separate system? Then plumb the two pool skimmers, drains, and returns off of a separate pump and filter? Would the water levels stay maintained? Or could all three be plumbed together with a good variable speed pump, along with the option of the heater, heating the two pools OR the spa? One pool company suggested we keep the hot tub hydraulics completely separate. Then, operate the two Kayak pools as one large pool by connecting the ends of a large (4 or 5 inch) pipe into the lower section of the walls on each pool. This would hopefully equalize the water level in each pool (if that is an issue). If we did that, should one pool draw from the other pool before going to the pump, with the returns going back into both? Or should the pump draw from both at the same time and return into both to maintain water levels?

Any thoughts, ideas, direction, or schematics that anyone would be kind enough to share, would be so greatly appreciated. As you can see, I’m somewhat at a loss for ideas. I have searched all over the internet and I cannot find any sort of schematic for two separate pools with a hot tub configuration.

Thank you in advance for your thoughts and insight.
Ken B.

Recap of Setup:
The pools are rectangle and have four foot walls. The hot tub is kidney shaped and close to 4 feet deep, with steps and seating.
(#1) Pool is a Kayak On-Ground 12 x 24’ = +7,539 Gallons (using an approx. 3.5 foot water level with 4 foot walls)
(#2) Pool is a Kayak On-Ground 16 x 32’ = +13,404 Gallons (using an approx. 3.5 foot water level with 4 foot walls)
(#3) Spa is approximately 10ft x 7ft x 4ft deep = approximately 900 gallons (approximated S.W.A.G. because of the kidney shape with steps and the seating.)
The pools and hot tub are exactly the same elevation.
Rural country setting necessitates a propane fueled heater. Or possibly a heat pump but I thought the heat rate would be too slow for a weekend use spa.

 

[Mr Bruce]

I think you are in rarely charted territory for sure. One thing, I would strongly consider running the spa separately from the other 2 pools for no other reason you can continue to use it during the fall/winter/spring months. That is a pretty big heat sink to try to keep warm, especially for a propane heater which I believe is about the most expensive way to heat water there is.

It might be possible to circulate the water so: Pool1 -> pump/filter -> Pool2 -> [pump/filter?] -> Pool1; I can't think of any reason off the top of my head not to, except maybe twice the number of places for problems/end of life to occur. Maybe one of our stronger "hardware" folks will chime in.

 

[Dirk]

Now this is a thread I want to follow! One of the more unique questions posed here, I'd guess.

Equalizing the two pools, and treating it as one body of water, would certainly simplify everything. You could conceivably do everything with one pump, spa, too. And automation could run everything. Run all the returns back to the pad, and a skimmer from each pool, along with the intake of the spa, and use actuated 3-way valves to switch the filtering system from pool to spa. Even add an SWG to chlorinate everything.

The wild card would be the dosing, and the circulation of chemicals across all three bodies.

I don't have any experience designing a pool's hydraulic systems. But I wouldn't rely on the equalizer pipe for circulation. It'd only balance the levels. You'd have to draw from each pool from independent skimmers, and mix (balance) that water through a three-way valve in front of the pump. Then return that filtered/chlorinated water back to each pool through returns either balanced by more 3-ways, or each return on it's own independent valve. Then just monitor the two pools' chemistry, and adjust the various valves for balancing the water circulation between the two, until you're satisfied that both pools are getting adequate chemical dosing. Something like that.

You could treat the pools and spa all separately, and use valves to run each independently through your filter and heater, but if there is an automation system that could do that, it'd be expensive. My automation could handle two bodies of water, but not three. So I think you'd need two automation systems to run the three bodies separately. Run it as two (pools as one, and spa), and one automation controller could handle both.

I could be missing some important component of this scheme that would negate the whole idea, but if not, what do you have to lose? Start with one pump, one controller, one SWG and the valves you'll need to pull this all off, and just connect everything with having to redo it all in mind if it doesn't work. By that I mean, leave plenty of PVC pipe between everything (pump, filter, valves, etc) so you can cut it all apart and glue it back together with more pumps and filters should the "one-pool" attempt fail.

I say put this all together as one giant pool, with lots of returns and two skimmers, with a built-in spa, and see if it works.

We need pic's, please!!

 

[Kennerb4]

Thanks for your quick reply, Mr. Bruce. I'm sorry I have not had the opportunity to do the same. You know, I never really thought we would use the spa beyond the pool season but I am starting to rethink it. If that is the case, I could definitely see a separate spa pump/filter setup. That will probably be the way that I will end up going. I agree about the expense of propane. I have gone full circle during the past year with this whole heater selection issue. I originally thought I wanted a 140k BTU HeatPro Low Ambient Heat Pump. But with this being a weekend place, I thought the heat up time would be way too long unless we left it running all week which is kind of crazy (like you said, that I pretty big heat sink) lol... Then I thought a pure electric heater would be best, but then I started researching kilowatt hour/rates and thought that it would be somewhat expensive to operate.

Then my latest thought was to go with a larger, propane heater, with the option of heating the pool/s if necessary. Propane in my area is running $1.79 per gallon. I could get a 250 gallon tank of propane delivered for less than $500.00 dollars, which I'm thinking should last the entire swim season (May through September) using a 250,000 btu heater.

I'm completely open to other thoughts because I have zero experience on this matter. I should probably put a new post out there about heater selection. It's just that my classic "over research and procrastination" has put behind the eight ball, so I need to act quickly (at least according to my wife) ha... Thanks again for your thoughts and advice.

 

[cfherrman]

I would get a large sand filter, biggest you can afford, 24"-31", and two 2hp or 3hp vsp, probably. Run one pump and filter together and have it suck from one pool but return into the other, then the second pump just sucks from (first pool with the filter return) and returns into the other pool (where the filter sucks). All your water will be filtered and be circulated. You will have to check both skimmers. A swg cell rated for 40k on either pump would be great since you are not there all the time. Getting 3hp vsp pumps means you set it and leave it, easier.

I feel like I would want to have option to circulate the spa water to the pool and the option to isolate it for heat. I don't have a spa or a hot tub.

A balance line of 2" is fine

 

[Kennerb4]

Hello Dirk. Thanks for taking the time to reply and explain that option. Sorry I have not had time to respond earlier. I certainly mean no disrespect.

Man, I like the way you are thinking along the lines of balancing all three skimmers (and drains) to mix all water before the pump. Then balance the water distribution going back. I'm not sure I have the knowledge or experience to pull that off but I'll get some paper and give it a shot. Off the top of my head, I get most confused when thinking about how to heat say, just the spa. But it may become a little more clear once I start sketching it out on paper.

You don't know how much I appreciate you taking the time to respond with your thoughts and ideas.

The contractor who is building the additional decking is just getting ready to start. I'm trying to get the spa set at the right elevation before he starts so the decking can be installed around it. As you suggested, I will certainly get some pictures when underway. Thanks again.

 

[Dirk]

I had originally thought of CF’s idea, of two pumps criss-crossing, but then I’m not sure how that would integrate with automation, especially with the spa. I really think you could do it all with one pump. I don’t run a spa, but my understanding is you use two actuated valves that “connect” all the returns, drains and skimmers/intakes from either the spa or the pool to your pump/filter/heater/chlorination system, one at a time. I think you schedule each during the day to satisfy the needs of each: heat, filtering, circulation, sanitation, etc. And then you can override the pool schedule and switch to spa, on the fly, to ready the spa for a dunk. Something like that. That can all be done by automation, and remotely. That’s if you run both pools as one. If you run the two pools separately, with two pumps, I think you’d have to have a second, completely independent setup for the spa: pump, filter and heater = $$$$.

I think the best thing you can do is run everything back to the pad on its own dedicated pipe: returns, skimmers, drains, etc. that way you can try the one-pump idea, and if that doesn’t work, then you can add more gear and just reconfigure the pipes at the pad.

I really do think you’ll be able to balance the two pools with three-ways to provide adequate mixing of chemicals. It just might take a little extra pump runtime to get it done. My guess is that is still going to be more economical than running two pumps.

All wild speculation on my part, but it’s what I’d try first, to see if it’d work...

 

[Dirk]

This is what I’m describing:



Sorry, trying to do this in my car while waiting for my three-year-old to wake up from her nap...

 

[Kennerb4]

Hello CF. Thanks for your reply. I certainly agree. The two pump system would keep the water filtered and circulated. Plus it would simplify the water chemistry by operating the two pools as one, but if possible, I would like to get away from running two pumps, well I guess it would mean three pumps with the spa. Glad you said that about a 2" balance pipe as opposed large one. I was thinking a 2" would serve the same equalizing purpose and be much less prone to leaks. Didn't even give a thought to an swg. I need to do some research but that could simplify this whole process even more. I'm sure my goal is similar to everyone else here: To simplify pool ownership in the most cost effective manner... thanks again for welcome thoughts.

 

[Kennerb4]

@Dirk
Just saw your post. Wow, this sounds (and looks) fantastic. I just have a minute right now to respond but I would really like to discuss more later. This looks like it would work great for what I need!!! One of the many things I really like about this setup is the option for an automated program to turn on the heater for the spa only, "or" to heat the pools when needed. The only minus is the need to heat both pools together, which I really don't need to do but that's okay. It's a small price you pay for mixing the two pools and having them operate as one. The cost savings from using a single pump, will probably outweigh the cost of the infrequent times when the two pools would need to be heated. I understand the "in theory" part of this setup but I'm really excited about researching this type of setup more when I get a second. Thanks so much.

 

[Dirk]

@Dirk
Just saw your post. Wow, this sounds (and looks) fantastic. I just have a minute right now to respond but I would really like to discuss more later. This looks like it would work great for what I need!!! One of the many things I really like about this setup is the option for an automated program to turn on the heater for the spa only, "or" to heat the pools when needed. The only minus is the need to heat both pools together, which I really don't need to do but that's okay. It's a small price you pay for mixing the two pools and having them operate as one. The cost savings from using a single pump, will probably outweigh the cost of the infrequent times when the two pools would need to be heated. I understand the "in theory" part of this setup but I'm really excited about researching this type of setup more when I get a second. Thanks so much.

Just to be clear, I've never designed or built even the simplest pool plumbing system, so I'm just spit-ballin' with ya. You'd need to get another set, or ten, of eyes on this, for sure. And while you're checkin' on this idea:

I didn't realize being able to heat one pool at a time was a goal. With my schematic, it is possible to do that, manually for sure, with just the turn of two three-ways. But that would in essence isolate the other pool from filtering and circulation, too, not just heat. Theoretically you could filter and heat one pool during some number of hours of the day, and then filter the other pool during some other set of hours, with no heat. But you'd have to manage the valves, and you'd have to test and dose the two pools as two pools, if you were running them that way for any extended period. Whether that would be worth the trouble or not is up to you. And it's conceivable you could automate that, by adding two more actuators, but how exactly you'd orchestrate that with one controller is beyond my experience.

The other wild card is the winterizing. I don't winterize my pool, so I can't speak to that either. Someone who does would have to look at the drawing and tell you if you can winterize one or both pools, just by closing valves, and still be able to leave the pump and heater online to run just the spa. Or the spa and one pool. The valves are there to do it, I just don't know if you can drop the pool levels and blowout the pipes, etc (whatever one does to winterize), and leave water in some other part of the system.

--- Updated ---

I was advised to delete the following post. And I decided to take half of this one down, too. Too much "hypothetical" and not enough facts. I hope I was clear enough that I was just brain-stroming with the OP, and any idea I might offer was just based on my imagination and not on any real-world experience plumbing even one body of water, let alone three.

One of the things I most appreciate about this site is that it is curated, and most every post is reviewed by experts, and posts that contain information that doesn't support TFPC, or are otherwise inaccurate, are either corrected or taken down. I'm happy to contribute here, and equally happy to be corrected!

 

[Dirk]

--- Deleted (See above) ---

 

[PoolguyinCT]

Are the pools level to each other? That’s the first question.

- running too vessels from one mechanical pad is not difficult.

& I doubt modulating valves are in the budget or even practical for such small systems.

So how close/ level are operating levels of each pool?

 

[Dirk]

Are the pools level to each other? That’s the first question.

- running too vessels from one mechanical pad is not difficult.

& I doubt modulating valves are in the budget or even practical for such small systems.

So how close/ level are operating levels of each pool?

Level! I knew I was forgetting something!! Thanks, PoolguyinCT.

And he's running three vessels (pool, pool, spa), not just two. So I wasn't sure how much of that could be automated, and how winterizing would work, if he wants to keep one or two vessels open year-round...

Would the schematic I drew work?

 

[PoolguyinCT]

In a Rube Goldberg fashion.. [emoji41][emoji2]

 

[cfherrman]

This is what I’m describing:

View attachment 76337

Sorry, trying to do this in my car while waiting for my three-year-old to wake up from her nap...

Good work.

Shouldn't the hot tub come with it's own system?

The cost of equipment above will come close to the two pumps and one filter system I thought of, then you have a pretty high labor cost. I just like things simple.

 

[Dirk]

Good work.

Shouldn't the hot tub come with it's own system?

The cost of equipment above will come close to the two pumps and one filter system I thought of, then you have a pretty high labor cost. I just like things simple.

How are you figuring that cost comparison? I'm only counting two extra three-ways that would be needed to eliminate the second pump. Everything else would be there anyway. If you add in the cost of an entire second system, to run the spa independently, that makes your math even worse.

All those two-way shut-off valves are optional, and are only there to balance the returns, not to balance the two pools (the two extra three-ways do that). So they would be in either setup, or not. They're not an additional expense (nor their labor or piping). The three-ways on the drains/skimmers are also there no matter how you balance the pools (ditto for labor and pipe). So they aren't an extra expense, either. And the actuated three-ways would also be there anyway, to swap the pump/filter/heater/swg between spa and pool.

Unless I misunderstood your post, you're proposing three pumps, two filters, two heaters and two swgs?

Hard to describe and/or picture these postulations without drawings...

 

[cfherrman]

If the hot tub comes as it's own system,vyou just leave it alone.

Then you have one skimmer and return for each pool, two pumps and one filter and around 20' of pipe to hook everything up, and maybe a line to tie in the tub.

I'm thinking of a bottle Rocket compared to your falcon heavy multi purpose heavy lift to Mars rocket. They both work.

 

[Dirk]

If the hot tub comes as it's own system,vyou just leave it alone.

Then you have one skimmer and return for each pool, two pumps and one filter and around 20' of pipe to hook everything up, and maybe a line to tie in the tub.

I'm thinking of a bottle Rocket compared to your falcon heavy multi purpose heavy lift to Mars rocket. They both work.

Right, one of those deals where there are many ways to solve it. For sure.

But he's got some specific goals that might not be met with the bottle rocket... Plus a chunk of his plumbing is already in, so even my schematic wouldn't be fully realized. It'll be some sort of morph of one or more of our ideas...

 

[Kennerb4]

Are the pools level to each other? That’s the first question.

- running too vessels from one mechanical pad is not difficult.

& I doubt modulating valves are in the budget or even practical for such small systems.

So how close/ level are operating levels of each pool?

Hello poolguy. Yes, all three are exactly at the same elevation and leveled using a transit. Thank you for verifying.