Okay, it doesn’t have the relaxing jets of a traditional hot tub, but if you own a pool with a heater, you know there are times when you just want the water to be warmer. The 150,000 BTU heater used with this 24-foot X 52-inch pool takes about an hour to warm all the water by one degree Fahrenheit. By adding a small soft “inflatable ring pool”, you can have a small sanctuary 10 degrees warmer than the rest of the pool in about 25 minutes. In about an hour and a half, the temperature can get 20 degrees warmer, all with the same heater.

This 8-foot stand-alone pool (photo below) works perfectly as a hot tub right out of the box and has nothing sharp that could damage your pool liner. It retails for well under $80.00 (you don’t need the filter and can buy the pool without it). Besides this, all that’s needed are a couple of pool hoses and some rope to hold your new floating hot tub in one place.

Setting up the hot tub is simple. Inflate the ring to about 3/4s of its air capacity and throw it in the pool. To keep it in position, tie it off to the pool between the pool-heater water outlet and the water return outlet(s) by using two ropes looped through two of the hot tub drain holes. Adjust the temperature on the pool heater to the desired temperature you want the hot tub to be. Temporarily insert something into the hot tub drain holes to slow the water from getting through until the hot tub fills and takes shape. Next, attach a short flexible pool hose to the pool-heater water outlet on your pool and use it to fill the hot tub. The hose needs to continue to fill the hot tub as long as it’s in use so you may need to secure the end of the hose to keep it in the hot tub. The water coming from my pool heater gets to a maximum of 10 degrees warmer than the temperature of the pool water going in. It takes my small 2500 GPH pump about 25 min to fill the hot tub. Lastly, once filled, remove whatever you used to temporarily block the drain holes in the hot tub so the water can drain out, warming the pool, and circulate back through the system. Here’s the tricky part. If the drain holes are too big, the hot tub will not hold its shape, use something to reduce their size. If the drain holes are too small, the inflatable ring will get pulled underwater and become too stressed, you need to make them bigger. Every pool is different depending on the size of the pump and the brand of “inflatable ring” pool you use for the hot tub. Mine worked perfectly with the 3 existing drain holes.

By adding the optional hose shown in the diagram above, you can increase the temperature of the water going into the heater, therefore, increasing the temperature of the the water coming out to more than 10 degrees above the pool temperature. In the 50/50 split shown in the diagram, the water in the hot tub will eventually rise to 20 degrees warmer than the pool water.

Getting in and out of the hot tub from the main pool is easy. You can just swim over the soft top, or since the ring is only filled to 75 percent of its air capacity, it is easy to push it down below the surface and step in and out. Because the water level inside the hot tub ends up being slightly higher than the pool water after you adjust the size of the drains described above, the inflatable ring appears to be completely inflated.

Removing the hot tub only takes a few minutes. Disconnect the hose(s), deflate the ring, and rotate the pool while underwater to the upside-down position. Pull up on the bottom, dumping out the water as you go, then let dry in the sun. The heat from whatever warm water that was in the hot tub is instantly transferred to the pool.

Dave Lister

listerlogic.com

Note: This is an original idea by me but there may be similar products or patents already.  I am not an expert, if you attempt to build always consult with an expert and check with all local codes and laws.  Build at your own risk.