Lowering CYA

[jrsdws]

Ok...settled on stopping the draining process at about 60% removal...according to the pool calculator this should put my CYA level around 45 after refilling....which is underway. I worked for a while longer raking the bottom with the leaf basket and really pulled a bunch of decomposed leaves and crud out. The water was low enough and clear enough that when the crud settled again you could see where I dragged the basket.

I added 6 jugs of bleach but decided my circulation at this point probably isn't enough to really do it any good. I think I'll just get it all filled and get the pool pump and filter running and start fresh.

The "Best Guess" chart says for +shock+ at my expected CYA level to go for 30ppm. The Calculator says that's 11 jugs!!!!

Does this sound right or should I just go for the "shock" of 15ppm and maintain that until clear?

[aylad]

I am estimating your pool volume at just over 17K gallons. A 15 ppm shock level should be sufficient (I think the other shock column is for mustard algae victims) and it looks like 4 1/2 gallons should get you just over that, if you're starting from zero. I would maintain that 15 ppm as consistently as you can, brushing daily, watching pressure on filter and cleaning as it indicates.

By the way, have you had the well water tested for metals? Iron is common in well water, and will change the course of this advice, if present....\

Janet

[jrsdws]

Iron is present in our wells, however, both wells are suitable for drinking....as determined by the county health department. For the sake of the plumbing and fixtures, though, we do run an iron filter upon entry to the house.

I am filling from two different wells at the same time. The one that supplies the house is drilled at about 130' with a fabulous supply of water. The other is the old shallow dug well and is only used for filling the pool, watering, and car washes, etc.

Please do tell my new direction as I've probably been missing something for the last 5 years!!

[aylad]

Are you filtering the iron from the well that's being used to fill the pool? If your pool water contains iron, you may need to add a metal sequestrant, because water containing iron that is exposed to high chlorine levels often turns brownish. However, if you've added the 10 gallon dose already, and the water didn't turn any strange color, then possibly your iron levels aren't high enough to matter, so i that case just keep it at shock level until the green starts clearing up. Keep your pump running, clean it as pressure indicates.

Just out of curiosity, when you said you had multiple algae blooms last year, were you actually seeing algae growing, or was the water just turning green? Did that happen after additions of new water?

Janet

Janet

[jrsdws]

Water to the pool is directly out of the well...no filtering. Initial fill 6 years ago was all municipal water, but all subsequent spring openings and any other additions have been with the well water. I've never had any brownish discoloration in that time.

Last year I had had two or three battles with algae. It got away from me in a matter of a couple of days when I was away on work travel. I would return to green water and no detectable chlorine levels. This is when I bought the good test kit and found the high CYA level so I figured I never really had a full algae kill and I was never keeping the chlorine level high enough to prevent this with the CYA level so high. You could see the algae growing in it. Once it was in conjuction with the corn tassling and I though it was just that, but it soon got out of control.

I am still filling at this point. I should have everything full and up and running by mid-day tomorrow (Saturday).

[jrsdws]

Pool is full and pump/filter are running with skimmer sock in place. Lot's of crud in it so going to take a bunch of attention this weekend.

I let the pool pump run for about an hour and checked all pool chemistry....CYA is at about 40....so goal #1 achieved.

I'm going to start a new thread and post all of my numbers with some questions...as some things are pretty far out of whack.

Thanks all for the help thus far.

[aylad]

I'm going to close this thread so you can continue to get helpful responses on the other one. When we get two threads going about the same pool, it gets confusing.

Janet