To floc or not to floc ...

[DavidS]

Hi
Really appreciate all the help here. We are in the process of opening a swamp, have ordered the recommended test because those test strips are useless, so we are testing at the pool store. Used the pool calculator to shock up to 14 (est) at night, have added CYA. Test results 24hours later:
FC 4.0
CC 0.0
pH 7.6
CYA 35
TA 119

We have vacuumed, backwashed, filter looks good. We will have both AM and PM samples tested tonight so that we can get a better idea of what is happening overnight. The water is blue, algae looks dead, but the water is very cloudy. The pool store wants us to use floc. Should we?
Thanks!

 

[JohnT]

You need to keep your chlorine higher if you are fighting algae. If you let it get below shock level the algae will get going again.

 

[frustratedpoolmom]

Welcome!

How long did you shock? Our criteria is you are done shocking are:

You lose less than 1ppm of FC overnight;
Your CC is .5 or less;
Your water is clear.

So keep the FC up to shock level and check to see if it's holding overnight. Sand filters can take a while to clear up dead algae.

Floc is almost never necessary, though some people like to use it depsite the expense. In your case I would not, give the filter a chance to do it's job. You just added CYA and floc would mean vacuming to waste so much of your CYA level will drop.

Keep the FC up and make certain that everything is dead. Have you read about Defeating Algae in Pool School?