Hi all - long time Pool Solutions member, but first time TFP poster (longtime lurker).
I've had my IG 11K Salt pool since August of 2006 and have been testing my water daily (at least pH and Chlorine) since startup with a Taylor K-2005 test kit. I've noticed over the last 2-3 months that my pH likes to hang around 7.8 for about 5-6 days before it finally creeps up to 8.0. It will shoot from 7.2 to 7.6 in a matter of 2 or 3 days, then slow down as it approaches the 7.8 level. I started thinking, this isn't too bad - I'll just run my pool at a high pH, no problem.
I started having doubts a few weeks ago - and I'm not sure if I'm just misreading my pH colors, or if something else is going on. Last week, I watched my pH sit at 7.8 for 5 days, and finally to 7.9. In reading my pH test results, I have always considered 7.8 to be reddish, and if it starts to get a pinkish hue, I always considered it to be past 7.8, but if it wasn't as pink as the 8.0 color standard I always considered it to be 7.9. I dumped 32 oz of acid which should have lowered my pH to 7.2 (according to BleachCalc, but also confirmed by my historical acid usage).
After letting the pump run for about 3 hours, I tested my pH again, only to be baffled to get a 7.5 pH reading! Now the doubts are swimming all through my head!
- was I misreading my pH test and my pH was really well into the 8's? If so, does anyone have any tips for reading the pH test more accurately?
- is there something else that could cause the acid to somehow not be as strong? I keep my borates level at 50 ppm. Do the borates somehow cause more acid to be needed to lower the pH a determined amount?
- I haven't checked the % concentration of the acid that I have, but this is the same acid I have always purchased at Lowes (around $9 for a pack of 1-gallon jugs)
Any ideas would very much be appreciated!