Is this algae?

[dmorriso]

I've had this on my grout and deck corners since I moved in in June. When the water level goes up due to rain, it goes away. When I lower it, it comes back. I've scrubbed with bleach and a scouring pad (even removing grout in the process), and it comes back. I've never (knock on wood) had an algae problem in the pool, even when I was on tabs and accidentally let the FC hit 0.

Regardless of what it is, any bright ideas on how to kill it for good? Could I apply ployquat directly?

Other than this, the pool is consistently sparkling via TFP method, with minimal bleach use (about 0.7ppm a day) and passing OCLT.

 

[duraleigh]

That is a great hidey-hole for algae and that's what you have got. It'll be a continual battle until you fix the hole, but I would suggest you make up a squirt bottle (all plastic....no metal) and fill it with 25% Clorox and the rest water.

Spray it in there every time you think about it and you'll eventually get it killed. It may take a while.

 

[dmorriso]

That is a great hidey-hole for algae and that's what you have got.

Why don't I get algae in the pool (or fail OCLT) when the water touches it - because I'm vigilant about my FC level?

Does applying an algaecide directly work any better than bleach? Straight bleach on the grout didn't seem to do the trick, but maybe a toothbrush wasn't saturated enough. I'll try the spray bottle approach.

Thanks!

 

[Crackerjack4u]

Algaecide is a preventive to try to help prevent algae growth, but most will do little to kill it. Some algaecide contain metals that can cause staining to your pool etc. Chlorine is your best choice because getting enough chlorine on there for long enough it will kill it out.

 

[domct203]

Why don't I get algae in the pool (or fail OCLT) when the water touches it - because I'm vigilant about my FC level?

Does applying an algaecide directly work any better than bleach? Straight bleach on the grout didn't seem to do the trick, but maybe a toothbrush wasn't saturated enough. I'll try the spray bottle approach.

Thanks!

Your pool should remain clear as long as you maintain the proper FC level for your CYA level.

A one-time application is not going to kill the algae in the grout, especially with it being on a vertical surface. You will need to apply the chlorine/water mix and scrub often to maintain a residual chlorine level long enough to kill the algae. The more often the better.

Dom