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

[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.

[Tredge]

It does both.

I have a very Deep pool (11' 40,000 gallons) and the first 2 years I had no cover on it.

These last 2 years I've had a clear cover and I can state with certainty that it does indeed make a difference (no experience with other colors). ~10 degrees for me if I keep it covered every night.

I've noticed it helps a lot with evaporation which makes perhaps 80%+ of the heat retention. The water a few inches under the cover gets very warm but doesnt make a huge difference once you stir it up...especially in a deep pool.

I've also tried the liquid fish and those do help but only 2-3 degrees at most under optimal conditions. They do make stuff float on the surface a bit better which helps keep the bottom a little cleaner...but thats hardly a reason so use them.

[CarlD]

Yeah, evaporation is endothermic so it sucks energy (ie, heat) out of the pool when a breeze is blowing. You lose water AND heat at the same time...plus you have heat loss due to convection--the warmer water rises to the top because it's lighter, it warms the air above it, which gets lighter and rises, dropping more cool air onto the water, which now has to heat it....etc.

[deanbrew]

About a month ago when I opened my pool and put the solar cover on, it heated up about 3 degrees per day - went from 69 to 72 to 75 to 78 to 81 in four sunny days. I very much doubt I would have gotten that kind of increase without the solar cover, particularly since a couple of those days were sunny but not hot. Certainly, it helps the water retain heat at night, but I also think it adds heat, especially on a sunny day. I leave it on almost all the time, except in the middle of summer when the pool water gets too warm and feels like bathwater.

[fog80]

About a month ago when I opened my pool and put the solar cover on, it heated up about 3 degrees per day - went from 69 to 72 to 75 to 78 to 81 in four sunny days. I very much doubt I would have gotten that kind of increase without the solar cover, particularly since a couple of those days were sunny but not hot. Certainly, it helps the water retain heat at night, but I also think it adds heat, especially on a sunny day. I leave it on almost all the time, except in the middle of summer when the pool water gets too warm and feels like bathwater.

what kind of cover do you have (color, opaque etc).

I am looking at purchasing a cover and roller set from BJ's but I'm not sure if it is the right one.

[brent.roberts]

I recently went into a local major pool store and asked for a clear cover and they looked at me like I had rocks in my head.

I suspect the "blue" idea was to attract attention to the "product" to help sell more.

If you want to keep solar gain down in a car or in a room in your house, you tint the windows don't you ????

So they tell me the blue cover generates heat. Yeah sure. Then they put in the air bubbles that create an insulation layer the keeps a large part of that heat on the top surface of the cover. No thanks. Give me clear. Let the radiation penetrate the pool as much as possible.

My wife likes it at 90 degrees.

We are heating a 16x32 IG with solar panels and have a lot of wind in top of the hill where the pool sits. The water loss through evaporation is terrific. Maybe Chem Geek can tell us how many calories are lost when 1/4" of water evaporates. It's a big number and will translate into a lot of degrees.

I find the biggest reduction in loss is at night. To conserve your heat make sure you cover at night.

If your pool is in a well protected area and not subject to much wind, covering during the day is not so important, but will still make a difference.

With the tests I've tried, get a clear cover, run the pump intermittently so the water is moving under the cover and transfers the heat away from the cover resulting in less loss back up throught the cover.

The "heavy duty diamond" covers are just that ... heavy. After they start to break down and some bubbles break and others lose the air in them, they don't float to well. That means water on top of the cover and that means evaporation again and ..... why did we put the cover on the first place ... to stop the evaporation.

Get the lightest, clearest, cheapest cover you can find. It won't last anyway. Keep the water off the top of it. Protect it when its rolled up and you'll get the best bang for your buck.

You can tell this is a favorite rant of mine.

Good luck

[fcfrey]

Just to throw in my 2 cents. I have had 3 different colors over 5 years --- silver, Blue and now a clear "Extruded" one. I bought this one from SPC this spring http://www.poolproducts.com/ I am very satisfied with this one and do get temp gain ---- the other thing they state is that they do not have to be covered when they are rolled up. Mine has a 10 year warranty (manufacturers defects) which does not mean much since they will blame failure on chemicals anyway.

[deanbrew]

what kind of cover do you have (color, opaque etc).

I am looking at purchasing a cover and roller set from BJ's but I'm not sure if it is the right one.

Mine is just a basic blue cover, sort of like bubble wrap. Not the absolute cheapest, but fairly inexpensive. I'm sure there are colors and styles that might do a better job, but this one works pretty well.

[chem geek]

The ideal cover would totally block UV light so that chlorine won't breakdown from sunlight's UV rays. It would completely pass through visible light and most infrared. It would completely block heat from convection and diffusion (very little gets radiated back out from the pool as infrared -- it's not THAT hot) so would be a good insulator for heat.

I don't think such a cover exists. Most that pass through sunlight seem to pass through a lot of UV. So the clear bubble pack variety are probably best if you want heating since they pass through most of the light while still being good insulators. If you want to minimize chlorine loss, then an opaque cover is best though a blue cover MIGHT block UV (since it reflects blue) while letting other visible light through (or it might let blue light through -- ideally it would be like blue-blocker sunglasses that look orange when looking through them).

My own pool cover is an opaque safety cover and changes the heat loss at night from around 6F without the cover to 3F with the cover. If I had a true solar cover (bubble pack) the pool would probably lose half what it currently does -- probably around 1.5F. But at least I can roll mine with an electric motor so the convenience outweighed the lower insulating efficiency.

Richard

[stelr92]

I too would like to say that getting a solar cover has been a worthwhile purchase for my little 18foot round pool. I really like to have the water warm, and with the midwest heat that we have been having lately and abundance of sunshine, my pool has been sitting at a spa like 100 degrees for the last week now. I am just using a blue cheapie that I got for 60 dollars, I notice that after a good 4 - 5 hours of sunshine, the water in the first foot or so really heats up, so I have my pump filter set to go from 11:30am - 12:30pm, then again at 5:30pm - 12:00am so I can circulate as much warm water as possible. Last season without the cover the warmest the pool ever got was 82 degrees, and this was with a few straight weeks of 100+ degree temps! Other advantages include the amount of chlorine the pool needs has greatly reduced, and loss of water due to evaporation is also greatly reduced.