Pool chem great but having some algae

[phillipjko]

Chemistry is
Ch 1-1.5
FC 2
TA 150
PH 8.4
Calcium 400
CYA 140

Before the readings above the pool was nearly at the dot with PH 7.6, TA 90 and CYA at 80. algae is like very light greenish type along the pool lines. Using algaecide will help if I am away for 3 weeks with pool being closed? Thanks

[FormerBromineUser]

You can use 60% algaecide. Did you get your pH lowered?

[CarlD]

FBU means there's only one algaecide we recommend: Polyquat 60%. It's not a brand, it's a type under various labels. The key is there should be one active ingredient:
It should say "Poly...<something long and unpronounceable> 60%" That's the stuff. Any other algaecide is just asking for trouble.

But your numbers concern me if they are right. FC=2, pH=8.4, CYA=140 Your calcium and TA are a bit high but with a liner pool they are still low enough to be irrelevant.

Those first 3 mean trouble. You MUST get your pH down to 7.8 or less immediately! Or check the numbers.

A CYA of 80 means you must keep FC between 5 and 10 and shock at 20. But your current CYA of 140 means you need to maintain an FC of 8-15ppm and shock at 25ppm until it's clear.

With either set of numbers if your FC was that low I'd be surprised if you did NOT have algae!

[FormerBromineUser]

Thanks Carl! Didn't realize I had actually posted that incomplete comment... It was to work on later.