Love TFP !! pH bounce + pool tech / necessity for trichlor tabs

[Reade]

What an amazing resource TFP has been. Quickly fell into problems with CYA after pool opened last August. Drained and refilled 1/3 to bring CYA down to ~55. Fired pool service. Fired Leslie's (will never go there again, for ANYTHING). Learned everything I know from TFP and things have gone swimmingly. Why is it I feel I know more than the service companies?

I will be in and out of town on business most of the summer and have no choice but to hire a service company (ASP-Mesa). I did much research and liked the reviews they got on Google, and the way they handled complaints. Last week was our first service. I had just added some baking soda to bring the TA up a bit. Naturally the pH went up. I planned to bring it into balance the following day, when I got a call from P-tech saying he was on his way (a day early). So I thought I'd let him do it. I warned him it was high. (It was -maybe- a little above 8)

He dumped 1.5 gallons of MA (31.45 baume) into my pool. In the same spot. I had a heart attack, but figuring he knew what he was doing, I let it go even though I'd never needed that much to bring it in balance.

He thought it would bring it to 7.0 or 7.1. I tested after he left and it took 12 drops of acid demand to get it to a 7. And now the TA was 60. I added 5# baking soda and added ~2 inches of water with a spray hose to create some aeration. pH was now roughly 6.6. TA was 140. Like swimming in 7-Up, only less pleasant.

pH ticked up throughout the week. was above 8 on 5th day. Added 4ppm FC. + 4 doses of MA--I wanted pH to be around 7 (actual probably 7.2 TA=130 FC=6) when he came back, because I did not want him thinking he needed to add another gallon of MA. I just checked it again today, (the 8th day. Ptech to come today) and it was again 8. I've always had a bit of a pH up-bounce. Figure it is the liquid chlorine and nature of AZ water. But it has never been so dramatic. 7.2 to 8+ in two days?!!

Would a TA of 120-130 pull the pH up that quickly? Or a possibly high salt content? (bi product of 8months liquid chlorine) ? Or--did the low pH leach the calcium out of the plaster?

Also, any advice for my 5 months pool service madness? They use trichlor tabs. Which, I think, is necessary for a once-per-week service. I'd like to keep the CYA from going too high again. I figure their monthly backwashing should help. I'll take over again in Oct. I keep the pH ~7.4-7.6 when I'm in charge, but it it is going to ratchet up like that, the Ptech will have to bring it low at the start of the week. Or is it better to let it ride on the high end?

As of this moment:
FC=6 CYA=60 TA=~110-120 pH=7.2 Calcium=700 (up from a steady 6months of ~530)

Thanks so much!
Jude Reade

 

[borjis]

Have you tried allowing your TA to sit at 60 for a week and see what the ph does?

For some it has fixed the wild ph fluctuations & rises. Some go as low as 50.

Each pool is different though.

 

[DaninFLA]

the high TA is raising the pH. is there a waterfall or anything else providing high aeration? are the return jets pointed at the surface and creating a lot of turbulence? Your TA was fine before (60) and to increase the pH you should have used borax to raise the pH, which raises the pH but leaves your TA about the same. The baking soda increased your TA, which in turn is causing your rise in pH. the solution is to keep lowering your pH with muriatic acid and over time that will lower your TA until you get to a point where it will rise a lot slower


as far as the tablets go, with using the service its going to be hard to avoid. you are probably going to have to do a drain/refill later this year to lower your CYA.

 

[RobbieH]

I would just float some tablets and not hire a service if you are not out of town much. Or hire a housesitter and have some little bottles of bleach with instructions to pour them in, or big bottles with simple instructions such as "pour one of these containers full (cup, whatever) into the pool each day."

1.5 gallons of MA in your pool is absolutely insane. If my pool gets up over 8, it takes a gallon to bring mine to 7.2, and my pool is FIVE TIMES the size of yours.

 

[PAGirl]

Have you thought about a SWG. Then the pool guy would only have to check the PH, and possibly add a little MA on his visit. (With strict instructions not to mess with anything else, lol.)