Hot Tub DIY From A Stock Tank Pool

Disclosure: We are not electricians. Please read how we turned our stock tank pool into hot tub at your own discretion. Always use/consult a certified electrician when installing your pool and pool heater. Always disconnect your pool pump and heater from electricity before getting in the water.

Well, it’s the first day of Fall, and folks are starting to shut down their stock tank pools. And while it’s always sad to see summer fade away, I know you are so excited about everything cozy. This is why we are excited to show you how we turned our stock tank pool into a hot tub!

Back in 2018 we turned our stock tank pool into a hot tub, and it was A LOT of work! We rigged up an electrical heater (we literally built the entire thing) and got our 8’ pool up to a nice hot tub temperature. The only problem was that it took SO long to heat up. I think we ran it for an entire day, or two, to reach that temperature. And all the while the tank was letting out heat. Anyway, it’s safe to say that it wasn’t very efficient. It did work though, and some of you may have even seen the tutorial before we decided to take it down this year.

The good news is that we have figured out something better that is pretty simple to put together. We used this spa heater we found on Amazon. It’s very affordable, but it doesn’t have a plug end, which is where an electrician comes in. The heater connects inline to our pool pump hoses and turns on when there’s enough water flow to trigger it.


We are using the Intex 1000 GPH pool pump and it was strong enough to keep the heater on. We read some folks reviews saying they had a pump that wasn’t strong enough, but ours is working perfectly. This means you could use this heater with a 1000 GPH or anything bigger. I would not suggest using a smaller pump.

If you need instructions on how to install the Intex 1000 GPH pump, check out our video by clicking here!

We were very impressed with how fast this heated the water, given our past with heating the stock tank pool. But there is one very crucial thing you must do no matter what you heat your pool with- INSULATE!

Let me tell you, the metal on a stock tank pool is not going to keep the heat inside your pool. It’s going to let that heat out almost as fast as it comes in. We decided we needed to make a koozie or jacket of sorts for our stock tank. To do that we used reflectix, a very thick wool rug pad, and flannel fabric. You don’t have to go this route- there are many ways that you could insulate your stock tank pool. However, you definitely need to do something if you actually want to use your stock tank as a hot tub. You also need a cover. We plan on making an insulated cover, but for now we are draping a tarp over it and it’s working just fine!

We turned our heater off one evening and the water was at 102 degrees. In the morning the water was 94 degrees. This means that this stock tank koozie/jacket situation actually works and is crucial for being able to keep your hot tub water warm. You definitely don’t want to have to heat your water from something like 52 degrees every time you want to use it.

If you don’t want to deal with electric (besides your pump, of course) you can always opt for a gas tankless water heater. This one is a great option as it heats more water faster than other ones and it is specifically made for being outdoors!

Okay, so you probably want to know how I connected this part to our pump, and I will do my best to explain. Please note that these are instructions for using the 1000 GPH pump. I will note how to alter for the 1500 GPH Pump or 2500 GPH Pump. Here are all the things I purchased:

Step 1. Cut your PVC into two parts. I used a mitre saw and my pieces are 10” each.

Step 2. Attach the Type A Hose Adapters to the PVC. These fit on the inside of the pipe. You need one on each piece of PVC. I originally used sealant on to seal these two pieces, but the water pressure was too high on one side. I ended up using JB Weld Marine Weld on that side. I followed the instructions and then put the material on the outside of the adapter and the inside of the PVC pipe and let the pieces cure.

Step 3. (Skip this step for 1500 or 2500 GPH pumps.) Create the extra piece for the pump hose to connect to. I took a Swimline Adapter, cut off the section with the threads with a mitre saw, then sanded the edges. I then took Type B Hose Adapter and cut off the lip on the smaller end. This took some finagling but some wire cutters did the job best. I then fit the Type B Adapter into the Swimline adapter. It’s a tight fit, but I used Marine weld again to secure them to each other.

Step 4. Attach your PVC to the heater with PVC cement. Follow the instructions on the kit. The PVC pieces will fit right into the pieces attached to the pump.

Step 5. Once everything has cured for the correct times, it’s time to attach the heater section to the pool pump. Turn your plunger valves to the locked position. Disconnect the hose from the lower outlet plunger valve. If you have a 1500 or 2500 GPH pump, you will completely remove the hose and replace it with the new heater section. If you have the 1000 GPH pump, you will connect the hose to the extra piece from step 3 and then attach the heater to the plunger valve and the extra piece now attached to the hose.

Turn your pump on to make sure there aren’t any leaks and everything is flowing smoothly. If you heater is connected to electricity safely, it will automatically turn on when your pump flow water through it. So you’ll just sit back and relax and wait for the water to heat.

If you turn your stock tank pool into a hot tub this season, we’d love to see your pics! Tag us on Instagram @stocktankpool for a chance to be featured!


20 comments

  1. how's this working out for you? I've been trying to convince my wife of this venture.

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  2. I am curious if anyone knows of an automatic switch that would turn on the heater only when pump is on. If it got too hot, I could turn off pump but as a safety precaution, I don't want to heater on without the pump....

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  3. Thanks guys I'll do it on my pool,
    Heat the water a little to be more comfortable.

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  4. Do you use any chemicals to control the PH levels?

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  5. Hello ladies! Just wanted to wish you well! I can't wait for cocktail pool season and I bet you can't either - especially now that most of us are spending a lot more time at home these days. You guys are awesome!!

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  6. Hiw did the heater impact your electric bill?

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  7. So this is amazing!! My one question I cant seem to figure out how you've covered the heater, right now by description and diagram, the live wires look exposed. Am I missing something? Help! Thanks.

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  8. Hey guys, this project is awesome! We have had our stock tank pool since 2015 and every winter I am googling trying find a way to make it a hot tub! Our stock tank is in-ground and we surrounded it by brick pavers- we couldn’t insulate it at this point. Any ideas? I wonder if the ground surrounding the tub would provide some insulation, more so than the air if it was above ground? We are in NC so winters aren’t terribly cold. Would love to know your thoughts!

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    Replies
    1. We had someone else ask this same question recently. I feel like it'd definitely be better than the tank out in the open. You could work on insulating from the top too.

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    2. Thank you! You guys are awesome!

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  9. Hey,
    I followed your instructions to set up my pool initially, now trying to add the heater. I think I'm missing some parts that may not be listed on this blog post. What are the parts needed for the t and cap and to attach to the heater itself. The collars from the adapter are too small...do you have instructions that are photos, not video?

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  10. Hey Wanderer!

    We also followed your instructions to install our stock tank and we love it! Now we are wanting to convert it to a hot tub. We however have a 1500 gph pump. We ordered all the items you had listed, but the attachments are too big or too small. Any suggestions?

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  11. I've been able to get everything connected. What setting did you set the pump to? I'm not sure if it's heating or not. I replace the hardwire with an appropriate plug.

    Any insight will be helpful.

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  12. Hey folks following or attempting to do this:

    The pump featured here is for tank with less than 400 gallons of water. I have an 8ft tank and a Intex 1000 GPH pump and could not get this the pump working. I'm trying a different thermostat for a larger pool and will circle back if I can get it to work...

    Anyone looking for this pump, reply to me and I'll make you a good deal.

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  13. Hi there! How do you have the thermostat connected? I ordered the one linked, do you plug the heater into it or the pump? Any help would be GREATLY appreciated! xo

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  14. Thanks so much for this!!!! We have all the parts and the tub is insulted!! The problem is that all the warm water sits on top and the part of the hot tub that sits below the pump is still cold! Anyone run into that problem??

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  15. Thanks for this article, it was interesting to read about such an unusual device. My husband and I have been thinking about doing something like this for a long time, as we like to swim in the fresh air. We were thinking about building a pool ourselves, but our neighbor suggested we read the reviews on https://www.luxury-bath.reviews/ and see what their clients had to say about their pools and baths. We liked the reviews and decided to give their bathroom installation service a try.

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