Green, cloudy and foamy is no way to go through life, son

Filter pressure is steady. Pump is 3/4 HP, should be ok for 20,000 gal IG pool? The DE idea sounds great.

You need to be patient. There's nothing that will speed it up. You've been fighting foaming from one "magic potion"--algaecide.

We rarely ever suggest that someone add anything beyond the B-B-B basics...bleach, borax, baking soda, muriatic acid and CYA(stabilizer). The two most common additions to the list are Dry Acid in lieu of Muriatic (safer and easier to use) and one algaecide: Polyquat (a type, not a brand).
If people have special problems, like metals, we may recommend something. But everything else? Throw it away!

Carl

This is just a belated follow-up to report success with pool problem. I found $3/gallon 12% bleach at BJ's (and see it now at Ocean State Job Lot) and have used it generously. Pool finally cleared and has stayed clear. I have tried to maintain CYA but sock approach is not keeping up. Just added DE to sand filter and the water sparkles, although this may be my imagination. So thanks for all the great advice that was both effective and economical.

Now I am trying to summon the courage to deal with the metal stains......

I'm not sure I know what you mean by " I have tried to maintain CYA but sock approach is not keeping up." Once CYA is added, it pretty much stays in there all season. What is your volume and how much CYA have you added? Are you using any stabilized chlorine (Trichlor tabs or dichlor shock powder) and what is your CYA reading?

I have added about 8 lbs of CYA a pound at a time using the sock method for a 20,000 gal pool. I have seen (or thought I saw) an increase to a level of "30-50" using a color strip but then a reading of 0 several days later. Perhaps I am mis-reading the strip. I have used 2 lbs of dichlor shock powder only once when we went away for a weekend, otherwise it has all been bleach.

Test strips are useless and unreliable. Around here, we refer to them as goofy strips. As we recommended to you back in an earlier post on 6/12, you need to get a good kit.

8 lbs. of CYA in 20,000 gallons would have added 50ppm. Do NOT add any more. Also do not use any more dichlor shock or trichlor tabs as they also contain CYA in them.