Low TA and CH, is this ok

[richierich]

Here are my full set of results. Water at the moment is clear. Been keeping my FC at or around 8 all summer but occasionally even at 8 my water sometimes gets a tad cloudy and a little green and then I add about 8 ozs of Cal Hypo 68% (65% chlorine listed). I have a vinyl above ground pool (no heater). I should also add whenever the pool isn't in use we always have the solar cover on to reduce FC usage been burned up by the sun. My intex SWG isn't very good and we only run it about 3 hours a day since I have a 1 speed pump, so I supplement with about 2 cups of bleach 2 times a week.

using TF-100:
FC - 7.5
CYA - 60
PH - in between 7.2 and 7.5 color. Going to add about 7 ozs of borax to bring up a little
Salt - 3000
Calcium Hardness - 50
Total Alk - 40

 

[Texas Splash]

You can use Cal-Hypo for a while if you wish, but remember it adds calcium each time. Your vinyl pool doesn't not require calcium, just don't let the CH get too high (i.e. 400 - 500 or more). Your TA does need to come up. Use some baking soda to increase the TA to about 60 - 70 and you should be fine.

 

[richierich]

Ok thanks - So I'll leave CH alone. Wasn't sure if that being too low matter.
Regarding TA - what are the issues if it stays low? I thought that was a good thing since my PH literally always stays about 7.3-7.5 every year. Or does low TA tend to make PH drift down a bit?

 

[Texas Splash]

what are the issues if it stays low?

TA does a couple things. First, it helps to keep the pH fairly stable and eliminate erratic behavior. The lower the TA the lower the pH tends to fall. Your pH appears to be steady. so if that continues that's fine. The other thing is that for some pools allowing the pH to remain low for a long time can allow the water to become a bit corrosive. A pH of 7.3 - 7.5 should be fine as well. I suspect the low use of your SWG also comes into play as SWGs tend to create a little aeration and increase the pH a bit. If you're comfortable with the water and see no ill effects with your current TA/pH, you can leave things alone. But I wouldn't let the TA fall any further.

 

[richierich]

was reading that low CH could make a vinyl liner become brittle over time. Should I use calcium chloride to raise the level to like 150? I used the baking soda to raise TA to 60

 

[mknauss]

Calcium has no effect on modern day vinyl liners. Low pH will make vinyl liners become brittle and wrinkle.

 

[richierich]

ok thank you.