Some guy posted this in a forum:
I have a 5000 gallon above ground pool in my basement. It feels nice down there but the water is freezing. I have a tiny rear end pump on it right now that kind of flows water but I’m wanting to heat the hole pool to a reasonable temperature.
I want something cheap that won’t melt the pool as it is rubber. I know I’m not the only person out there with a pool in their basement.
Here are the responses:
some texas redneck
Please please please tell me that that’s a “wet location” rated lamp on a GFCI, and you have sump pumps from hell in your basement. It’s not an “if” it’s going to leak, it’s “when”, and you’re going to need some crazy pumps to keep up. When a rubber above ground pool lets go, it doesn’t spring a tiny leak, it usually just splits wide open. That fridge next to it becomes a major shock hazard if that happens since the compressor and cooling fan are at the bottom.
If that lamp isn’t outdoor rated AND isn’t on a GFCI, get rid of it and cover the box ASAP and disconnect all wiring to that box at the breaker panel. If someone were to reach up and touch that lamp and it wasn’t PERFECTLY grounded or they managed to somehow grab a live wire (say they touch a bulb and it shatters from the temp difference and they get a nice jolt of 120 volts), they’re loving dead along with anyone else in the pool….
Keep in mind that anything electrical down there will now have to be upgraded to “damp” location rated because of the humidity. If you have wood joists, you can say hello to mold and rot.
If you want it to be safe electrically, EVERY circuit in the basement will need to be GFCI. GFCIs get picky about motor loads, like fridges (like the one next to your pool).
Awesome idea in theory though, I give you a thumbs up for that. But in practice I’m looking at a loving death trap.
edit: Not to mention, once you start using chemicals in it (and you need to asap, that looks pretty cloudy), it’s not only going to stink up the basement, but everything above it. In other words, your entire house will smell like an indoor pool.
You need to find a way to SAFELY drain it (believe me your sump pump, if you even have one, isn’t up for the task). Then put a proper hot tub on your back porch, maybe with a canopy above it.
If you absolutely positively have to heat this death trap, find a good heater for that size, PUT IT ON A GFCI, and make sure it doesn’t touch the sides of the pool. As long as it’s only in contact with water, the surface of the heater will never exceed 212F/100C. I dare you to call your homeowner’s insurance about this to see what it’ll take to insure it though…
Just chiming in to tell you this is EXTREMELY DANGEROUS, both to your house and to your life! It may sound good on the surface, but is very shortsighted and a horrible idea. Seriously, if you want a basement hot tub, get a basement hot tub. Drain the pool, and put it up outside next summer instead.
Problems I see:
1) Lethal electric shock from the light right over the pool
2) Lethal electric shock from non-GFCI receptacles
3) Broken glass from the light right over the pool
4) Mold from the humidity
5) Rot from the humidity
6) Flood damage from constant splashing
7) Severe flood damage from when it inevitably leaks
8) Structural damage from rot stemming from ignored flood damage
9) Loss of value of your home leading to be unable to sell it
At the very least, install GFCI on your basement receptacle string ($15, maybe $30 if there are two strings) replace the light above the pool with one that’s rated for damp conditions and more damage resistant, and buy a dehumidifier.
And to answer your question: Do nothing. Do absolutely nothing. It will warm up to room temperature on its own, you don’t have to do anything but wait.
Finally a real answer to the question:
Assuming this is an underground basement and the floor is concrete, I would say heating that pool will be impossible or at least impractical. At a depth of 4′ down, the Earth maintains a temperature of around 50 degrees, and your pool will act as a large heat sink and constantly seek to attain that temperature. Given that the pool won’t reap the benefits of solar heating, your monthly expenditure on electricity to maintain a comfortable temperature will be ridiculous.
Oh, plus that pool is going to ruin your house for all aforementioned reasons.