New pool owner, ph dropping after couple of days

Grankel1 · Jul 10, 2015

Hello everyone,

I'm a new pool owner so I apologize if this has already been posted else where. I have a new above ground doughboy pool 21' round. The pool is half in ground with half the pool being 6'2" deep and the other half is 4'. I'm having issues with maintaining my current PH. Here are my numbers. (Taylor test kit 2006)

FC: (measured at .2ppm) 2.2ppm
CC: 0
TA: 90-110ppm (no chemicals added, besides chlorine tested 2 days apart. We did get heavy rain)
CH: 100ppm
CYA: not registering anything(solution not cloudy)

I do have hard plumbing with a Hayward CL200 chlorinator set to 4. I run my 1hp pump for 7 hours a day.(from 7:30pm-11pm, then again from 5am-8:30am off peak hours) based off some specs (85 GPM) I estimated I'm turning over the water approx. 2-3 times a day.

I have been having issues with my PH dropping from 7.4 to 7.0 over a course of a few days. I have added a PH plus and have got it back up to 7.4-7.5 with in 4 hours for it to drop again in a couple of days. My TA seems to be in range or should I push it up to 120ppm? Any help and advice would be great. The water is still pretty cold 67 degrees F (just filled up a week ago) but crystal clear.

Again thanks, this forum is awesome!!

Greg

lefty51 · Jul 10, 2015

Hello and Welcome to TFP :wave:

, nice looking pool. That's cool that you have that kind of depth with an AGP.
First I would add stabilizer to get that CYA up to at least 30ppm. Since you have the tab chlorinator, you can use tri chlor tabs to raise CYA, but after that I would suggest using plain old bleach as the tabs will continue to raise CYA until it's way to high. CYA will help hold on to chlorine so your not losing it to sunlight and bather load daily. Pool math calculator can help you figure what to add and how much.

As far as PH dropping, an easier way to raise it without having to add chemicals and risk sending TA higher (it's on the edge of too high now), if you have a way of aerating, such as pointing return up so it will "break the surface of the water" or adding a fountain that will raise PH through air naturally and not affect TA.

Hope that helps, and ask all the questions you want, the pros are standing by

Grankel1 · Jul 10, 2015

Thank you for the reply!!! It took me a while to hand dig it, but it was worth it

. Quick question, I do have the 3" tabs that I bought at a pool supply store, does that contain chlorine and the stabilizer? Or is tri chlor something different? When I purchased it I thought it said that it did contain something that had CYA in it. I'm sure I could have read something wrong somewhere and made a mistake on what I purchased.

Was it not wise to put a chlorinator in-line? I was hoping that it would maintain good levels by having it there. Thanks again for the reply

lefty51 · Jul 10, 2015

No, it's not bad to have the inline. I had one for 14 years before going to SWG. It's just that mine got bad and gunky over time, but that was all we were using to chlorinate. There are two kinds of tabs, Di chlor which adds calcium and tri chlor which adds CYA. There are a number of people who have a setup like yours and they come in handy when you will be away for a few days to keep the chlorine levels up AND when your CYA needs a boost like yours does now. It's just in the long run you will want to use liquid chlorine or plain old bleach as that will maintain your FC without adding something else you don't need.

If your CYA gets too high, it will take more chlorine to maintain a healthy FC and the only way to lower CYA is with water replacement.

As far as aerating to raise PH, there are some threads on how to build and aerator to attach to your return. I should figure out how to post a picture of mine.

pooldv · Jul 10, 2015

Trichlor and dichlor both have CYA. And the do drop PH. More here, Pool School - How to Chlorinate Your Pool

Please add your pool info to your sig as shown here, Pool School - Getting Started

lefty51 · Jul 10, 2015

pooldv said:
Trichlor and dichlor both have CYA. And the do drop PH. More here, Pool School - How to Chlorinate Your Pool

Please add your pool info to your sig as shown here, Pool School - Getting Started

Thanks pooldv for correcting me. I'm the one who needs to reread

. So both of them will drop PH. Would he be better off adding stabilizer instead of using tabs so PH won't drop ?

Grankel1 · Jul 10, 2015

Thanks for the replies, I am currently using Tri-chlor, I will point my return up to aerate the water, I would like to see a picture of your return if you can post. I will re-read some more info in the link provide. Thanks again

lefty51 · Jul 10, 2015

It's cal hypo that adds calcium not CYA, boy I need to retain knowledge better :hammer:

I went looking for the posts that show homemade aerators, but pictures aren't showing up for me. I'll have to wait for my youngest to get home to use her fancy picture phone. (I wonder if she can make phones calls with it ?)
Anyway my returns are threaded returns. I'm not sure if your AGP has threaded returns or not. Either way, someone on here has a way to aerate your water, I'm sure