How to either cheaply heat a pool, or heat a pool for one day?

I am having a graduation party in May, and my pool tends to be cold at this time of year. It usually sits around 63-66 degrees. I would really like people to be able to swim at the party, and the only way I realistically see that happening is if I can get the pool up to at least 70, possibly approaching 75 degrees.

Does anyone have any advice on how I can do this without spending thousands on a heater? Ideally, I would spend as little as possible with as much benefit as possible.

I know that solar covers work, but in the past they have only increased our pools temperature by around 2 degrees. It's a start, but is there anything else I can do?

Thanks so much!!!

The only people who consistently enjoy swimming in a 70 degree pool in May are 11 year old boys, and residents of Maine who think they are having a heat wave when the water at the beach gets up to 60! For most others, 75 is comfortable for many under FULL sun; but it has to be 80+ before most people enjoy a pool on an overcast day.

Those are pretty much the 'people' parameters you have to work with. Now for the water ones. You want 10 degrees of heat; that's a lot.

Solar heating systems -- the flat black poly panels -- might give you that . . . if you have sunny days, well placed panels, cover the pool at night, don't circulate the water through the panels at night, and so on. And such a system might only cost you a few hundred dollars . . . if you install it yourself (correctly), and get a good deal on the panels, and have a fairly small pool.

But, when you're asking for 10+ degrees of reliable (can-count-on-the-pool-for-the-party-plans) pool heat, you're asking for a lot.

Al (Poconos, one of the moderators) can probably come up with something that will work, but it will take a lot of tinkering.

BTW, if you have an inground pool, and paint it with Viking Blue epoxy, that's probably good for 3 - 5 degrees in a typical May.

Welcome to the forum.
Sorry I don't have any solution to your problem. Believe me, if I did I would have done it myself many years ago. The things that Ben mentioned, solar cover and solar panels, do work but as he said, not guaranteed when you need it. Unfortunately a gas heater is the only device I know of that has enough BTU capacity to do what you want as fast as you want.
Al

Thanks, Al. I knew of there was a way to do what he wanted, you'd know.

Know? I didn't know.

So, now I know that what I thought I knew before -- that there was no method -- was knowledge and not it's absence. (it's almost 2am; I need to go to bed.)

I had a similar situation early last year for similar reasons to you.

I did find a cheap solution which I know the "chemicals" guys are going to slam me for.
The cost was less than $30 (estimated fuel cost) for a temperature increase of 25 plus degrees in a few hours in a 6000 gallon pool.

I have multiple zones on my boiler.
I "tapped" into the laundry area zone with a regular garden hose on the drain/bleed hose bib.
I threw the hose on the ground next to the pool. I then turned up the thermostat in that area of the house to 90 degrees so that the circulator pump and demand for heat (Oil burner) was constantly running. I let it run for about 20 - 30 minutes, constantly checking with a bucket to see if the hot water coming out was clean. When it finally was, I threw it in the pool and waited 4 hours. I had to let “some” water from the lowest drain (THE COLD END) every hour or so.
By mid early afternoon, the pool had gone from 56 deg to 82 deg.

I tested the water with the Taylor kit (recommended by Ben and many others) the day before and the day after. There was little to no difference and the water seemed fine while swimming and was easily maintainable for the remainder of the season.
My pool cost less than $300 so I was not too concerned about what I might do to the liner. As it turned out, there was no apparent damage.

This is what I did. That doesn’t mean it is what you should do, just food for thought.

Hi Pete;

I'm glad it worked for you. But, I wouldn't recommend it for ANYONE else. Here's why:

Most boilers used for home heating use recirculated water. In some cases, this water is treated with toxic chemicals, which help protect the piping, but don't hurt people . . . . because people are never in that water. In other cases, the piping & boiler are corrosion resistant, so long as not too much fresh water is added, but that water will itself become metal contaminated. And there are still other cases.

The bottom line is: if someone knows enough to KNOW that they can do what you did, without damage to their pool or heating system, then they won't need to ask how to do it here. But, if they do ask, we have to assume that they do NOT know, and don't have the skill to determine whether they can, or not.

There are many things I've done on pools and with pool equipment that I'd never mention here, because they are "don't try this at home, unless you are an expert" sort of things.

What you've suggested worked well, and economically, for you. That doesn't mean it's appropriate for someone who may know know whether they have a steam or hot water system, or whether their water make up control is capable of feeding a pool without damage.

Fair enough.

But the only reason I ever came to this site in the first place, was to find out if anyone had ever built a shallow end for an above ground pool and how they did it. I didn't find anything here, but after I came up with my own solution, decided to post it here in case others like me were looking for ideas.
I would probably have never have come here if all I wanted was "run of the mill" stuff since that is documented in plenty of other places.

I am not suggesting to the OP that this is what he should do or that it is safe in all applications.
It is just what I did. It worked. Even if my idea suggested some crazy “out there” stuff, if I was looking for ideas and everyone else to date had said it can’t be done, I would have been glad to find at least one way to do it. Even if that method was not for me.
I hope a great site that this one continues posting out of the box stuff like this for those that are looking.

I can accept that.

But I always have to keep in mind that Google sees and remembers all these posts, and that they stick around for years. So, when I or one of the mods, sees a solution that could work for some, but be dangerous or damaging for many, we try to counter-post or add a correction. It's not necessarily for you, or even for the OP, but for the guy that may be reading this 3 years from now!

There are posts here that I've never read -- many of them -- but when we see one, we try to 'fix' it, so that it's reasonably safe, not just for knowledgeable and skilled people, but also for those who aren't

Good luck . . . and I'm glad you found a solution that worked for you.

Heating a 6000 gallon pool is a tough chore, heating a 15,000 or 20,000 gallon pool quickly is tougher.

The goal is, as Poconos says, to pump BTUs into your water. One BTU is the amount of energy to heat one pound of water 1 degree F.

10,000 gallons is over 85,000 pounds of water. That means you need 85-90,000 BTUs to raise your water 1 degree. You'll need 10-15 times that to get you water just to the mid-70's from the mid-60's

Heaters are rated in BTUs per hour......For one day? I have NO idea how much NG or Propane that would take.

Just my take.

Carl