Do I need DE?

What is DE and do I need to add some to my sand filter? I have seen in here where some are adding it to their filter to help clear the water. What about clarifier? I have added bleach and kept the FC levels way up since Thursday and have seen virtually no change at all. Is this something that will finally just clear up overnight or is it more gradual?
Update on my problem: (27000 - vinyl - swg)
Water is clean and clear, but just a little cloudy. It only seems to be noticable in the deep end due to the depth, I guess.:mad: :mad: :mad: :mad:
pH is 7.6
FC is somewhere around 20 (cheap test-dilution method - waiting on Ben's)
cya seems to be very high now - about 90 (again cheap test)
vinyl pool so I haven't been too concerned with Calcium Hardness
Alk is around 100.
Pool store said I don't have any CC, but my cheap test doesn't check for them
I can't lie, I am getting VERY VERY frustrated. I hate going out there because I know it is going to look the same. It can't be in very bad shape because it has been absolutely perfect for the past 3 years. Now this...

Any help or direction would be GREATLY appreciated.
Brad

DE is Diotomaceous Earth (even if I spelled it wrong). It's a very fine filtering medium, usually used in pools with DE filters. But lately we have found that 1 cup added to a sand filter can help it filter much finer particles.

Sand filters sometimes cannot get the finest stuff--but the DE seems to help that. It sounds like you have a lot of dead algae and either the system isn't sucking it in from parts of the pool or your sand filter isn't filtering it. Are you sure you are using filter sand? Are you sure your filter is running correctly? All should be checked..

I assume it is filter sand. I don't know I've never had any trouble. I do think that is what I see sitting on the bottom of the pool, in the cracks every morning - my pump runs at night. I just figured it is okay for some of the sand to come through, it gets sucked up by the pool sweep. I just thought of something - maybe I need to run the pump more. It is on a 12 hour timer right now. Should I turn off the SWG while bleach shocking? If so, why?
Thanks again,
Brad

If you are blowing sand through, then I'm wondering if your pump is mis-matched to your filter and is too powerful. Your filter MUST have a greater capacity than your pump--or you get stuff blowing through. Most people have bigger pumps than they need.

If your pump is too big, you can get an impeller replacement that lowers the GPM of the pump.

Carl,
How do you know if the pump is to big?

Hi, Brad,

Given your indistinct method of measuring Cl and your CYA of 90 (maybe), I submit that the filter is not your issue.

To get that pool to breakpoint chlorination and clear it up, you should be running your Cl up to around 20-22ppm and KEEPING IT THERE until your water clears.

Run your pump 24/7 'til the water clears as well.

Can't answer about the SWG but I'd turn it off....why produce Cl when you've already got it in there?

You simply have not kept your Cl high enough...long enough. :) :)

Additionally, it the cheapest, simplest thing to try. We all need to remember what our Dads taught us..........check the easiest things first. :) :)

I measured the CL with a "drop based" test from WalMart. It's the one where it turns yellow. It only measures to 5ppm so I diluted with three parts water and still got 5 which told me it's at least 20ppm. According to the "black dot" test for cya - it should be around 90, but the pool store told me last week that it was 42 and I've only added 3lbs since. So I am really chasing my tail here. I will keep the CL up, but it only checks for TC. Does anyone know if there is still a pretty good waiting list on Ben's kits? Thanks for the replies and please keep em coming. It's very encouraging (right now I need that).

Thanks again,
Brad

Hi, Brad,

I'll repeat three words in my post...."KEEP IT THERE". If your Cl was 20 last night, it won't be this morning.

I think you're on the right track but it is imperative you keep bringing your Cl back up to 20 or so every chance you can.....three times each day is not too much.

Your water will sparkle shortly. :) :)