Algae Blooms with FC

[gpete]

This is my first post but have been reading posts and doing my own testing for a year now.

My problem is algae blooms that return with FC greater than 4. After a 12 inch rainstorm last year I started having some problems. When I got the pool ready to swim in April, I noted gray slimy material, which brushed away easily. I brought up to MSL and held for a few days. The next rain we had, the pool got cloudy even though the FC was 4 and found more of the gray slimy stuff and brushed it all, and opened the lights to clean out the nooks. Passed the OFCT and let it come back down.

We had rain last week and I immediately brought up to regular shock level. Still yesterday the filter pressure started climbing, and today I noted a little cloudiness, bur did not find any slimy material. The Pool chemistry this morning was:

FC 4.5
CYA 50
PH 7.5
TA 900

I have already brought the FC up to 32. Any other suggestions?

 

[woodyp]

Your cya is a bit low for a SWG. We recommend 70-80. Maintain the SLAM process until you pass alll 3 criteria.

 

[gpete]

So I did the SLAM process 3 weeks ago and passed all 3 criteria. The FC has not been below 4.0 since. Does this seem to be Mustard Algae even though it appears gray?

 

[zea3]

What type of filter do you have?

 

[gpete]

DE Filter

 

[zea3]

If you have not done a thorough cleaning on the DE filter lately I would open it up and hose everything off. Is the gray stuff still slimy feeling? Any trees or landscaping next to the pool?

 

[RobbieH]

When are you testing FC? With low CYA and a SWG, you'll probably find the morning FC is higher than evening FC, especially if you only run the pump at night or if you run 24x7.