Quote Originally Posted by PoolDoc View Post
Hi Tabitha;

Be cautious about your pH. As your chlorine level goes above 10, your pH readings, if measured with phenol red drops, will be less and less accurate. At 18 ppm . . . unless you are using a calibrated pH meter, you really don't know what your pH is.

Regarding the algae -- are you saying that you have algae in the pits and rough places at the water line?

If so, lowering the water level, and using a 1:10 spray of polyquat will probably work. Just make sure you use a CLEAN sprayer, with no herbicide or pesticide residue.

Or, if you've got an old clean sprayer that you don't mind ruining, spraying with straight bleach, and then 'pressure washing' with a hose and nozzle and the re-spraying will probably work.

But, it depends on how deep the rough spots are: you can only kill algae you can reach!

Once the algae's gone we'll need to see what the situation is with your pH.

Ben
"PoolDoc"
OK, I'm gonna leave the pH alone for now, then.

Yes, the algae is in the very shallow pits (maybe 1/16 of an inch deep or less) that exist just above the waterline where calcium has built up and is rough because of the pebble tech finish.

I thought about spraying/scrubbing with bleach, but wondered why the stuff is there in the first place??? It is about 105 degrees here today and very low humidity. I've kept the chlorine levels in the range recommended her for my CYA levels. Why the heck are these little splotches of algae hanging on? I am hoping this round of shocking will kill it once and for all.

Back to the original question: any ideas about why my pH level goes up so fast? I've been taking it down around 7.6 but it is up to 8.0 within 3-5 days. The fill water is around 7.6, so I am not sure what's going on. Is it the relatively higher chlorine levels (not shock level) making it test higher than it really is?

Thanks!