Finally - 17 months later my PH stabilized!

[skylar18]

My PB said it would take over a year but I didn't believe him. Pool was put in July 1. 2013 and I have had to put in MA at least every 4 days to keep it down to 7.5. Last summer I only had to put in 128 oz of bleach, the salt chlorine generator kept the chlorine level fine. However 20 oz's of MA every 3-4 days was driving me insane. I test every day so I know all my levels are perfect but it would be nice to go awhile without having to add anything! Finally 3 weeks ago it was like a switch was turned off. I have only put in about 20 oz's during the 3 week period.

I wondered if it was the water getting colder but I don't think so, The PH levels never stabilized last winter. Is 17 months normal?

 

[Divin Dave]

Yes, more than a year for it to stabilize seems normal. New plaster is a bear for the first year or so.
Your TA level has a lot to do with it too.
If you might post a full set of test results, someone could either give you a warm fuzzy feeling, or advise you of any other adjustments to be made.

 

[skylar18]

Sure! Here they are:

FC 4
PH 7.6
TA 70
CH 320
CYA 70
Salt 2900 - That is what it reads but it is probably at 3200-3300 based on water temperature. Learned my lesson once and put way to much salt in based on the salt reading with cold water!

Pool has never been shocked except the day the water was put in originally 17 months ago. Every time I go to the pool store to buy MA or part for my Polaris they tell me I have to shock it every few months and I am crazy. I ask why and they say to oxidize it. I ask what will that do and they say it breaks down all the things that is killed in the water by raising the Chlorine. I just say that is what I am doing by keeping my levels where they are and don't need to do it quickly. We usually agree to disagree at that point.

 

[chem geek]

Just tell them that with your method of properly maintaining an appropriate FC/CYA ratio, you are performing "continual oxidation". Shocking is just the pool store's way of making up for improper maintenance.

Now there are biological, not chemical, arguments for shocking that some people make in terms of preventing "chlorine resistance" of organisms, but this ignores the fact that chlorine kills through multiple chemical mechanisms (unlike antibiotics that attack single chemical/biological pathways) and that one maintains an active chlorine level higher than the barely inhibiting rate.

 

[HouTex]

I'm at 4+ years and my pH still hasn't stabilized! The pH rise for my pool is way less in the winter because the SWG is dialed way back. But when spring and summer hit my pH still rises. Lowering my TA helps a bit, but my water here in Houston has high TA so it's hard to keep TA below 70. During the summer I'm still adding about 30 oz. of MA every 10 to 14 days. I can't complain too much because other than topping up borates, salt and CYA once a year or so it's the only thing I routinely add to my pool.