Balancing the pool in AZ

[kotfu]

A couple months ago the pool guy told me it was time to drain and refill. So I decided to start taking care of the pool myself. Got a TF-100, went to pool school, and drained and refilled. I put some CYA in and started testing. Quickly learned that I would need a tanker truck of acid if I kept running the waterfall several hours a day, so have taken it off the timer and now only run it when we are swimming. Things were going OK, until it started getting hot (we are above 100 degrees every day now). I'm using a ton of chlorine, and still using plenty of acid to keep the pH in the right spot. Here's how the water tested today:

pH 7.6
FC 4
TA 60
CH 480
CYA 30

I did some poking around in the forums to see what others in hot, sunny locales have done. It looks like my TA is low, and so is my CYA. So what would you guys suggest? TA 90 CYA 70? Have previously had trouble with scaling, don't have any now. Haven't done borates yet, should I?

 

[jblizzle]

Welcome to TFP!!!

You biggest problem is the CYA being too low ... get that up to 50ppm and you should see reduced chlorine loss due to the sun. Although, you may want to raise the FC up towards shock level and perform the OCLT (pool-school/overnight_fc_test) to be sure there is nothing in the pool that would require the shock process before you raise the CYA.

The TA is fine ... if you raise it, that will just cause the pH to climb faster.

With the higher CH (which is only going to keep climbing), you have to keep a close eye on the pH to avoid the scaling.

Borates are completely optional and I would focus on everything else first.

 

[BoDarville]

kotfu:

Welcome to TFP

I would bump your CYA up in increments. I would first bump up the CYA to somewhere in the 40-50 ppm range and see how that works for you regarding daily FC loss due to sunlight. If you find you need to go higher than that, you will have some room to do so. Remember to use the Pool Calculator to determine the dosage and wait about a week before testing CYA again as it can take that long for the results to show up in your tests. It is much easier to add CYA than it is to get rid of it if it gets too high. As you increase CYA, your minimum FC will have to be adjusted up slightly. Refer to Chlorine/CYA Chart link in my sig.

I would leave TA where it is. As for pH, you have correctly surmised that running the fountains will cause your pH to drift up due to aeration. I would see how much difference your reduced fountain run time slows the pH from drifting up. Just keep in mind that with the CH a little on the high side, you may need to bring pH down a bit if it does get any higher than it is.

 

[Richard320]

Raise the CYA. Be aware that if you go above 50, your minimum FC is going to be above the max reading on the easy, daily, OTO tester and you'll be using the FAS-DPD powder test.

 

[kotfu]

Thanks for the tips. I raised the FC this afternoon, and it measured at 10 after the sun went down. I'll drag my carcass out of bed at o-dark-thiry in the morning to check how much I lost. I have enough CYA left to raise the level to 40, so I'll get out the socks (I have 3 skimmers) and start that if the FC looks good.