any way to control pH better?

[Furbabyvet]

Update: after keeping the chlorine at shock level for a couple of days, keeping the cover on the pool and scrubbing the algae with concentrated chlorine and a steel brush, I can't really see any algae any more. I know it may still be lurking, so I will keep my eye on it.

Thanks again for the help...

[PoolDoc]

Sounds good!

Thanks for the follow up info.

Ben

[waterbear]

I can observe that, in my experience with multiple large commercial pools managed with sodium hypochlorite (bleach) feed systems, I universally found that bleach fed pools 'wanted' to be at a pH of 7.6 or higher. I have no analytical explanation for this. But I can tell you that I discovered that if I let the pH float upwards, it usually -- but not always -- stopped before 8.0. I also found that if I operated the pools between 7.6 and 8.0 it took FAR less acid, than if I tried to operate the same pool between 7. 2 and 7.6. (Note to Chem Geek: yes, I tried it both ways on the SAME pools )
I have seen the same effect on customer's pools with SWGs and on the commercial pools with bleach feed systems also, and have discussed this before on different forums.



Most buffers have ranges over which they are effective, and other ranges over which they are not so effective. Cyanuric acid is an effective buffer at LOW pool pH levels, below 7.4 as I recall. Borax is an effective buffer at HIGH pH levels, above 8.0, I think.
At normal pool pH range most of the borate/boric acid buffer is in the form of boric acid and has a downward effect on pH when it starts to climb as opposed to the bicarbonate/carbonic acid buffer which causes ph to move toward 8.2

Just my 2 cents.

[Furbabyvet]

Another late update on the waterline algae problem. After using the BBB method all summer and attacking one more algae bloom (due to landscaping debris left in pool too long and my negligence), the waterline algae is completely gone. We did scrub with bleach, but I think it was just having balanced water over time that really fixed it.

I'm still amazed at how stable our pool has been using these simple concepts. Now that we have things under control, we're gonna try a SWCG to indulge my laziness even more. Ya'll are great. Thanks a million!

Tabitha