Wow.... Bleach consumption cut in half with a solar cover

[leejp]

Last sunday I installed a solar cover on our 18x36 26KG IG. Prior to the solar cover I had been consuming 2~3PPM/day with the CYA @~50.

The past week with the cover on I am down to 1~1.5PPM/day!

With the cover, I can keep the water temperature up and literally cut my bleach costs in 1/2! Why didn't I do this sooner?

[sunofthebeach]

I am on the other end of that.

This is my 1st year without a solar cover and I can't believe how much bleach/chlorine I am using.

[CarlD]

The cover will prevent chlorine from gassing off as fast. It may also block some of the UV rays that break FC down. If you have an opaque cover, blue on top, black on bottom, it will block far more UV, but may not heat as well.

We had, as our first pool, an Intex Donut. I would keep an opaque solar cover on it, then use the Intex pool cover, which tied over the sides, when we weren't using it or rain was on the horizon. Between the total blocking of UV, the almost complete prevention of gassing off, and the virtual blocking of contaminants getting into the little donut, I would find chlorine levels would be stable for days at a time, even as long as a week. Going on vacation was a snap--shock the pool and cover it and two weeks later it was fine.

[fog80]

Looks like I'm getting a solar cover. Which one is the best at heating the water?

[Spensar]

Looks like I'm getting a solar cover. Which one is the best at heating the water?

The heating effect is minimal for any of them. What it does do well is greatly help to retain heat overnight when the air temperature drops and you have a difference between the air and water temperature and without a cover your pool becomes a huge evaporation pan.

[CarlD]

I'm not sure where Spensar is getting his information. The insulating part is correct, but the heating part is not.

Solar covers can be VERY effective at heating your pool. They aren't nearly as effective as solar panels but they do work. It's just a matter of how much heat you need.

There's some debate as to whether opaque covers or clear covers work better. Opaque covers work by heating up and transferring the heat to the water by conduction. This does work and the water 4 to 6" below the cover will be quite warm, even hot. This then has to be distributed by the filter.

Clear covers work by acting as a greenhouse. The sunlight penetrates the cover, heats the water but the heat is trapped, rather than dissapating up into the air. This, too can be very effective.

Clear covers seem to work better when they are thicker providing more insulation.

My personal opinion is that thick, clear covers work best, followed by other clear covers, which are pretty much the same as opaque covers. Blue transparent covers are the worst. They don't pass enough light to heat effectively, but they don't heat up enough themselves to conduct heat to the water.

No matter the warranty all covers seem to go after about 3 years. They stretch (mine is already 2' longer than it was), then the bubbles start to pop. When they are rolled, it's best to keep them covered with a white opaque cover. Otherwise the sun bakes them and the inner layers get like an oven and start breaking down.

One thing I don't understand is why opaque covers are blue on top and black on bottom. I would think that black on top would absorb far more heat to be transferred.

Anyway, I've had experience with all three types and go for the thicker, clear covers now despite the expense.

A good roller is also a must. Those plastic rollers do not hold up, but I'm much happier with a metal-framed roller.

[cleancloths]

They are probably blue on top of the black for aesthetics - blue is nicer to look at.

[Spensar]

I'm not sure where Spensar is getting his information. The insulating part is correct, but the heating part is not.

Anyone I know in my neck of the woods that has a cover doesn't get much benefit from an increase in pool temperature. I am in Ontario and not in a real temperate area like you have in a lot of the US, so that is a caveat.

I cover my pool daily and tried not running the heater to see what the cover does alone. It didn't do much for raising the temp - you may get a couple of degrees, and it is at the top as you indicated. But the thermocline is thin and in our 16x32 inground pool the net effect isn't much. Perhaps if you are looking to bring water at a not bad temperature up a bit to a more comfortable zone, the cover will have some effect. No way in our area does sloar cover bring what was colder water up 5 degrees or so. That is heat increases attributable to the incremental benefit of a cover since even without a cover the water temperature will increase in hot sunny weather.

Anyway, that's IMHO and experience for conditions around Ottawa.

I just didn't want someone buying a cover and thinking it will give them a heat boost and be dissapointed. That has happened to a number of pool owners I've spoken to around here. Often summer night temperatures are a lower temperature than pool water and the cover helps to preserve the heat, even without a heater. I would recommend a cover for that reason and take whatever heating as a bonus.

I'll defer to the pros for other locations and my original statement may have been to broad.

[leejp]

I'm skeptical that the solar cover provides "heating" to the pool water. What the cover does for me is retain the heat when the temperatures drops at night (50~60*F around here recently).

I used to watch steam rise from the pool in the morning over my morning coffee... no more...

[CarlD]

It does both.

But if you don't have lots and lots of sun during the day (like 12 hours or more of direct sun) you'll not see a huge increase.

Still, if you really want to heat your pool, combine solar panels with the solar cover.