Does a solar cover help reduce algae growth??

[huskerfan]

PS. The morning after I first put our solar blanket on our pool, I had a scare! One of our cats walked on top of it and was sitting out in the middle of our pool on it! Mind you - we have friends who had a cat get in their pool and it tore up the liner trying to get out, so you know what was going through my mind! The blanket didn't even give as I called her over to the side as she walked on it. I took her off- then swatted her and yelled at her to get away from the pool, lol. Last time I seen her on it.

[chem geek]

I have an electric cover which is thinner than a solar cover and more opaque. It reduces the overnight temperature drop in half -- from 6ºF to 3ºF (when nights are around 55ºF and the pool starts out at 88ºF). It also cuts down chlorine breakdown (loss) from sunlight significantly. It also keeps all the junk out of the pool -- I forgot to close the cover this morning and my wife complained this evening about all the stuff that blew into the pool. It also keeps me from having to clean the cartridge filter (water is very expensive and sometimes in short supply where we live) more than once per season.

It is true that solar covers only last a few years and even the electric cover we have is only warranteed fully for 3 years and then pro-rated after that for a total of 7 years (so you can expect a life of 5-7 years). For us, the cover is worth it, but I can understand the hassle for some of rolling up a solar cover and the expense of having to replace it.

As for your original question about a solar cover and algae, I don't really know the answer. Following this forum's BBB method and Ben's chlorine table should prevent algae. A solar cover will still let sunlight in which algae could potentially use (while hopefully keeping out UV rays that breakdown chlorine).

Richard

[matt4x4]

Based on experience I have to say you should "air" your pool for 2 hours a day minimum while running the pump. If you miss a day, give it an extra 2 hours. If you leave the solar cover on indefinitely, you WILL get chlorine lock within a week, then algae will set in.
2-4 hours of "breathing" allows the chlorine that is eating algae (the chlorine that makes the pool smell) to gas off and leave only the free chlorine in your pool. Some think it keeps their chlorine in the pool longer, in a way it does, but it also keeps the wrong chlorine in your pool which is a bigger problem.
FUI - just because your pool is clean and clear, does not mean you have chlorine in there "waiting" for contminates, it is a continuous cycle without rest, ther chlorine is ALWAYS fighting something whether you can see it or not, I find if you can see it you're on your way to a problem, so keep it where you can't see it.

[chem geek]

Based on experience I have to say you should "air" your pool for 2 hours a day minimum while running the pump. If you miss a day, give it an extra 2 hours. If you leave the solar cover on indefinitely, you WILL get chlorine lock within a week, then algae will set in.

By chlorine lock, do you mean that the chlorine stops working? When this happens, do you measure CC > 0?

This has not been my experience with my opaque cover, but then it isn't a solar cover so perhaps keeping most of the light out inhibits algae growth. I agree that it is absolutely required to have air circulation when shocking and in theory if the chlorine is doing work continually then its byproducts should get "aired out". However, in practice, this hasn't been a problem for me. I'm guessing that in my particular case, there just isn't stuff in the pool for chlorine to "work on" except when we are using it in which case it is opened up for several hours (2-4). The pool gets used about 2-3 times during the week and 1-2 times on the weekend so it does get opened up about every other day or sometimes 3 days. I need to add chlorine about that often anyway.

Since adding liquid chlorine or bleach to the pool seems to perform a bit of a "mini-super-chlorination" effect (at least locally), and since SWG systems seem to have less trouble with their more continual dosing, it would seem that manually adding chlorine every day and keeping the cover open for an hour or two after doing so would be more effective. I've probably just been lucky I haven't had algae problems. Thanks for your post.

Richard