black algae back again

[mack51]

Well I can't wait on the CYA as I already put it in. My chlorine levels held for over 24hrs. How long should I keep it high 15ppm. Or should I say how long until the dreaded black algae is dead. I figure once I get it squared away I'll let my chlorine generator keep it in check. I'll definitely check out the BBB page. Thanks for your replies. I'll post in a week or so.
Mack51

[PoolDoc]

That's what I'm trying to tell you: there is not a point where you'll be able to say, "The black algae is dead".

You can get to, "The black algae is no longer visible, and is definitely not growing", but not to "It's dead."!

You have to hold it at shock levels (adjusted for your CYA level) AND brush it regularly, till it's no longer visible. THEN, you have to maintain good chlorine levels permanently (again, adjusted for CYA) to avoid regrowth.

Do NOT believe the pool ads that say this or that algaecide (usually containing copper) will eradicate it. I have, in the past, deliberately and heavily stained pools with copper, and then watched the black algae simply avoid the spots with the heaviest copper concentration (ie, stains).

Ben

[mack51]

OK I finally got my CYA up to 40 +- and my free chlorine at 13. PH is in good shape. The pool is looking very clear and clean. I still have some black spots lingering. They seem to be oblivious to any chemicals. I'm also using HTC super algae guard (dimethyl Benxyl Ammonium Chloride 30% and Dimethyl ethelbenzyl ammonium chloride 30%. I previously used some copper based algaecide from Leslie's which did absolutely nothing except make my wallet lighter. I had read somewhere in the forums to use Polyquat 60 but couldn't find any. IS this HTH stuff similar in chemical makeup to the Poly?? If this HTH garbage? If so what should I be using? And where can I find it. I'll probably hit it again with the power washer. That should break up the rest of the "black".
Thanks in advance to you all for your insight and wealth of knowledge.
mack51

[PoolDoc]

I'm also using HTC super algae guard (dimethyl Benxyl Ammonium Chloride 30% and Dimethyl ethelbenzyl ammonium chloride)

You are using up a good bit of your chlorine with that stuff -- one destroys the other. If that's your goal, that's a good thing I guess. But if it's not your goal, you're making a mess.

Mack, one of our rules here is we don't mix and match. You don't have to take our advice, but we're not going to spend time answering questions from folks that are trying to a little of this and a little of that. You'd be better off EITHER going with your pool store advice OR with our. Trying to do both wastes your time and ours, and doesn't help your pool.

Good luck!

PoolDoc