Oceansol

Thanks. I try to take it to 7.6 with acid weekly.

Waterbear and chemgeek: I, too, have creeping ph, but what about the ph of source water? My local city water has a water quality report online that shows ph of 7.8! This time of year I add an inch or two of water per week due to evaporation, so it seems like that alone would raise ph.

How about the rest of my post? Am I right?

Probably using the wrong term. Was reading about adding borax and acid by waterbear. Makes the pool sparkle... I'll try to find it. Please correct me if you can.

I have been reading many posts here after getting a smack-down by chemgeek (my post incorrectly put into the spa chemistry forum) regarding phosphates and nitrates. Chemgeek, thanks for opening my eyes! Some background: I have an 18k gallon in-ground, salt water pool built in mid 2007. My builder went belly up about 2 weeks after my pool was completed, so I've been kind of on my own with maintenance. I've been doing the maintenance myself, and on the advice of a friend started using a pool supply store for more in-depth water testing. 2- 1/2 years ago I was having an algae problem, and the pool store told me I have phosphates and particularly nitrates, and the best solution is to drain and refill. I did, and my problems went away. Recently, I began to have similar algae problems, so had him check, and guess what? I have phosphates and nitrates! I got suspicious, and came here, and received my well-deserved smack down. MY LESSONS: 1. FC and CYA and their relationship seem to be the key to algae control. 2. Phosphate and nitrate detection seems to be a way to sell pool chemicals. 3. Bromide additions (think that's right) are highly recommended. 4. TA can be lowered by reducing ph to 7.0, then aerating. 5. Pool pal is a great tool for android users. What am I mis-stating? What am I missing? I'm no chemist, but want to learn as much as I can about pool chemistry. Thank you Waterbear and Chem Geek!

Chemgeek, my cya WAS 50 a couple weeks ago, but I added more. Will check again today. Thanks for your help, and I'll update as I learn more.

So if my cya and fc are in those ranges, then I shouldn't even worry about phosphates or nitrates?

will I be able to keep up with the algae using a salt system?

Well, my pool guy (the pool supply store) says that excessive phosphates and nitrates are food for algae. Are you saying that I just need to up my chlorine? I have a salt system, and generally target chlorine at about 2.0-3.0.

I mistakenly posted this in spa forum, but have a pool. Sorry! (But question still valid, and I have a pool AND spa anyway!). Sorry!

I live in the San Diego area, and have a recurring nitrate problem. The obvious answer is urine, but I believe my kids don't per in the pool, and we only have pool parties a couple times each summer. My gardener only uses liquid fertilizer, and I've instructed him to be careful not to get any in the pool. There is a greenwaste recycling plant upwind of me about a mile, and the turn plant material into mulch. Often I can smell the "cooking" mulch, though it is not a very noticeable smell often. The only solution to nitrates that I am aware of is to drain and refill. My question is about the chemistry of nitrates: do the nitrates stay in the water during evaporation, and then build up? I should also mention that my city water contains approx 1.5ppm nitrates from a desal plant, so I'm continually adding nitrates to what I'm guessing is an increasing concentration of them. Please help me understand.

Also consider having your water checked for nitrates. I couldn't keep chlorine in the pool, had green algae, and the local national pool supply company doesn't check for nitrates. I suspected a bad cell, but a friend recommended that I have the water checked by a specialty pool outfit, small, local, and passionate, who also checks for nitrates. It was off the chart. Not sure how, but it was. Had to drain and refil