Low PH with SWG

[ChunkyGuacamole]

Hi All. I have an SWG pool completed last August, pebble finish. I was told I’d be having to add acid all the time to combat PH rise from the SWG. That was true at first, but now my PH seems to have stopped rising. I haven’t had to add any acid in weeks.

In fact, I find myself having to run my fountains to keep the PH at 7.6. I’m kind of at a loss as to why.

It rained a lot a couple weeks ago, so much so that I had to drain some water and readjust CH and CYA. Still need to add a bit more CYA, been doing it slowly.

FC 3
PH 7.5 seems to like it here
TA 90
CH 400
CYA 50
Salt 2800

Temp ranges 79 - 82. I run the VS pump from 10am -9pm at low speed and SWG at 75% currently. Pool is screened and stays clean.

Thanks in advance!

 

[mknauss]

Your SWCG is adding 5 ppm FC per day. That is great, but seems high, especially if you are testing at 3 ppm FC. Raising the CYA to 60 or 70 ppm should allow the FC to hold better if you are not dealing with any algae.

A SWCG has little effect on pH. pH is driven by new plaster in your case, then high TA fill water and / or excessive aeration.

 

[Jimrahbe]

Chunky,

Are you adding any acid? Things like pool store 'Shock" or chlorine tabs have acid in them..

I have three pools in the DFW area. I have to add a little MA to two of them every week to 10 days. The 3rd one only about once a month or longer.. They all have the same equipment are run the same way.

I guess my point is that not all SWCG pools have a problem with pH increasing.

Thanks,

Jim R.

 

[ChunkyGuacamole]

Ok, thanks. I have a Stenner pump with a storage tank to feed MA. I was running it for about 15 minutes a day before but turned it off when I noticed the PH was staying mostly stable.

I guess my new pool has finished it’s curing and just doesn’t need as much MA anymore.

I am working on raising the CYA. I just added 2 lbs of it and am waiting a couple days to test again. With all the rain I’ve had to drain water several times.

I don’t add anything from the pool store, really. No shock or anything. I keep a couple jugs of LC on hand mostly for my above ground spa but also in case the pool needs it. Just salt and the SWG mostly, a little calcium here and there when it rains a lot. We are on a well so if I do have to top off, it’s softened water that’s also run through a pretty beefy iron filter. But with all the rain, I rarely have to add water. Central Florida.