Dealing with algae for the first time

[harry5170]

All summer my pool has been very healthy! But three days ago I tested and had no FC. I noticed a light green coating on my white steps. After removing the solar cover, the deep part of the pool was also greenish with algae stuck to the liner. I have been shocking it now for three days. My latest measure was 60 CYA and the recommended 24 FC for shocking. The water is again clear, but I am getting deposits on the bottom of the pool that look like clumps of dirt. When hit with the broom, the clumps disappear in a small cloud of brown/green. I am hoping this is the dead algae that will have to be vacuumed out once I pass the overnight FC loss test.
All Summer I have maintained the pool at 4 to 7 FC. I did notice similar clumps on the bottom during the summer. They reacted the same way when hit with the brush. We thought it was dirt being blown in to the pool. I now believe that I may have had a slight algae bloom at the low end of the FC, and then killed it at the higher end, causing the dead algae on the bottom. Does this sound right?
My skimmer obviously won't remove much from the bottom, so is it safe to use my Hayward cleaner with a shock level present? Or should I wait til I pass the overnight FC loss, drop down to normal level, and vacuum.
As always, thanks in advance for all the help!

 

[RobbieH]

I think you are low for your FC with a CYA of 60. You should be in the middle 30's for the shock process if I've read correctly.

 

[thecanuck22]

personally i would be getting that stuff out of the pool as soon as possible, using your cleaning equipment with a high chlorine level the few times that it is needed to do so will not hurt it. Hitting the clumps with the broom so that they disperse is not what i would be doing either, just because you cant see it doesnt mean its not still there, suck it up, get rid of it ASAP.

 

[sbluhm]

According to the Chlorine/CYA chart, for a CYA of 60 your FC range should be min. 5, target of 7, so that's probably why you got algae. You didn't mention what you use for a source of chlorine and what you are using for shock, and what test kit you have?

I think once the algae is dead, it's dead, but I agree with vacuuming frequently, also I don't think it will hurt your equipment. Plus, more vacuuming and brushing will help with circulation.

Good luck!

 

[duraleigh]

Harry,

Your analysis appears very correct. Vacuuming the dead algae out is a good idea each day. I would not be the least concerned about the equipment in a shock level pool. Brushing is also a good idea during this process as it exposes all the remaining algae by suspending it in the water and killing it with the high level of chlorine.

Your pump should be running 24/7 during this period and you should backwash/clean your filter as needed.

 

[harry5170]

I think you are low for your FC with a CYA of 60. You should be in the middle 30's for the shock process if I've read correctly.

I took the shock level for my pool off the calculator. CYA 60 5 low 7 target and 24 ppm shock level.

 

[harry5170]

According to the Chlorine/CYA chart, for a CYA of 60 your FC range should be min. 5, target of 7, so that's probably why you got algae. You didn't mention what you use for a source of chlorine and what you are using for shock, and what test kit you have?

I think once the algae is dead, it's dead, but I agree with vacuuming frequently, also I don't think it will hurt your equipment. Plus, more vacuuming and brushing will help with circulation.

Good luck!

I have been brushing daily. I use 12% bleach, and I have the TFP 100 test kit. As far as the settling, it apears to be an effect of the movement of the water in the pool as it settles in the same places mostly. I would expect some organic material to remain after the algae is killed.