Sand filter failure

[Old Eagle]

I ended up getting my big shop vacuum and using it to pull the old sand out. I was careful to not suck up too much wet sand at a time before emptying the shop vac. It could hold 50 or 60 pounds but I would not be able enough to dump it out. Anyway, I got the sand all out in a fairly short time.

I cut up a bleach bottle to make a scoop to get the new sand out of a bag and I scooped sand out of the 50 pound bag until there was about 15 or 20 pounds left in the bag and then I lifted the bag and poured. Yes, I had tape over the center pipe opening. I put about a foot of water in the filter tank before starting to pour the sand in.

With all 250 pounds of sand in the filter tank, I put the top valve assembly back on, switched the valve to backwash and started the pump. When the view glass seemed completely clear, I switched to filtering, and now a lot of filtering and Kreepy Krauly work has to be done as I had killed off some green algae and the pool bottom was coated dark green.

Now I have a question. I am considering putting a liquid cover on the pool to help it save heat. Is that stuff going to foul the filter? Perhaps I shouldn't use it? Please CARL and any others, what do you think?

[Watermom]

The consensus around here is a big NO. Don't use the liquid cover on your pool.

[CarlD]

The consensus around here is a big NO. Don't use the liquid cover on your pool.

Exactly. Get a lighter cover (12 mil) and a cover reel. You'll be much happier.

[Old Eagle]

I believe you on the NO for the liquid cover. I can imagine it fouling the sand. Thank you both Watermom and Carl.
Another question: What about the idea of putting a limited amount of DE media on top of the sand in my sand filter? I have not done this, but it sounds logical when you think of the very fine particles that cloud a pool and keep going through the sand filter. In past years I did have good results using a clarifier solution to make the fine particles stop going through the sand filter. Now I am scared of adding anything but bleach and chemicals to adjust the PH.

[CarlD]

Both WaterMom and I, and many others have added DE and the results are excellent.
Record your pump's pressure (on high if a 2 spd or VS) apnd keep it running.
Add 1/4 cup of DE and wait 20 minutes.
Wait, oh 20 minutes and see if the pressure has increased by 1pound, if so you are done. If not, add another quarter cup and wait again repeat until you reach one pound increase in preassure.
If you go over more than two punds, just backwash it out and start again. Try 1/3 cup this time.
Once you find the right amount, which will be between 1/4 cup and one cup, just add that much everytime after you backwash.

That's all there is to it!

[Old Eagle]

Thanks much! That sounds like a very good plan. I had not thought about the backwash pulling the DE out but I guess that really will remove it. I am guessing that you put the DE in at the skimmer, but maybe at the pot just before the pump. I suppose either will work and the skimmer would be easier.

[CarlD]

No, no, it MUST be in the skimmer while the pump is running! You have to shut down the pump and shut off valves to open the pump's skimmer pot. Then it probably will clog and not distribute properly.
Don't make things tougher on yourself than you need to!