how long to clear

mikemedic

Well-known member
Apr 21, 2008
73
Ok so I am working on a green pool here in West Virginia. The outside temp has been 45 and rainy. I am 72 hrs into treating the green pool
CYA-45
FC-22
Alk-70
PH-7.2

I have kept the FC around 20 since Sat night. I added my first dose of bleach Sat Morning.

Does the cold temp have any effect on killing the algae?
My pool is vinyl and about 22000 gallons with a sand filter. I backwash ever day

How long may it take to clear up and have clear water?

Mike
 

JasonLion

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May 7, 2007
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Silver Spring, MD
There are two different stages in cleaning up the algae. First you need to kill it, which I think you have probably already done. You can tell that you have killed the algae by measuring the FC level in the evening and again early the next morning. If the FC level held steady overnight then the algae is dead.

The second stage is removing the dead algae from the water. Your filter will do this by it's self if you give it time and backwash/clean the filter as needed. If you run the pump 24/7 it can take the filter up to a week to clear the water completely. DE filters tend to be a bit faster. There are ways to speed up this process, but they aren't recommended unless you are in a great hurry.
 

JohnT

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Apr 4, 2007
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SW Indiana
To add to what Jason said, the first sign of progress you'll see (or may have already seen) is a change from green to a bluish-gray. That's an indicator that the algae is dead. From there, it's just a matter of filtering the dead stuff out. Vacuum or brush at least daily (or run an auto cleaner) to help the filter.
 

duraleigh

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Apr 1, 2007
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I backwash ever day
You'll get a little more efficient if you backwash every time your pressure increases by around 30% or more. That may be three times daily in the early stages and once every three days in the end stages.

If the pressure gets high and you don't backwash to get it down, you'll start pumping very little water and not doing much towards clearing your pool.
 

mikemedic

Well-known member
Apr 21, 2008
73
sounds good,
I have been doing this. I am pumping in Trichlor also so it's hard to tell if my FC is holding. Water is still green tinged today, not seeing the blueish grey yet, but green tinged, thats what makes me think its not dead.

Maybe I will cut out the trichlor for a day or two and retest am and pm, the trichlor doesnt seem to be dissapating very much.

I am in no hurry, we had snow here in WV this am, just hate seeing green water.

My PSI hasnt gone up much if any but still backwash ever evening.

ANy other suggestions other than time.

Thanks alot for all your input.

Mike
 

duraleigh

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Apr 1, 2007
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If your CYA tested at 45, I'd stop using tri-chlor. CYA will get too high.

Besides, it's really not very helpful when your trying to clear a pool...clorox is the best by far.
 

mikemedic

Well-known member
Apr 21, 2008
73
I use bleach all year, just use trichlor to help with the green pool. I use this if on vacation or knock the ph down which is very rare. I keep up with the bleach