PH steadily dropping...

[KineKilla]

I have gone from 7.4 to 7.0 since Tuesday. What would cause it to drop like that? Only thing I've done is put CYA in to bring it up from 0. In fact those socks are still in there dissolving.

TA remains high but constant.

#'s from tonight:

Salt 3200 ( dropped from 3400 yesterday!?)
FC 4
CC 0
PH 7
TA 150
Water Temp 70

Any ideas? Also, shouldn't I start to see my TA drop now that I'm down to 7 PH?

 

[Scuba_Steve]

CYA drops pH. It is an acid afterall...

As fr as I know, your TA will drop when your pH starts coming back up.

I am in the same boat. TA was 150. PH was 7.8.

Added CYA to bring it up to 70 for my SWG.

PH dropped to 6.8. My TA is slowly dropping now that the pH is rising from aeration.

 

[tim5055]

How are you adding chlorine? Tabs are acidic and will drop your pH, but not that quickly

 

[Richard320]

How much CYA did you add? If you tried to get all the way to 70, you added a bunch of CYA -- 300+ ounces. Plug that into Effects of Adding Chemicals down at the bottom of poolmath and you'll see how much it can affect pH. Some vigorous aeration will push the pH back up with no additional chemicals needed. Just aim the return up or devise some sort of sprinkler.

 

[KineKilla]

I'm slowly adding enough to get to 30 CYA. If everything in there were reading in tests I'd be around 20 so far.

I use the SWG to produce Chlorine. CYA and chlorination are the only things this pool has received since I opened it a few weeks ago.

 

[Richard320]

I'm slowly adding enough to get to 30 CYA. If everything in there were reading in tests I'd be around 20 so far.

I use the SWG to produce Chlorine. CYA and chlorination are the only things this pool has received since I opened it a few weeks ago.

To add 20 CYA in your pool, it says you add 88 oz. 88 oz will lower pH by .37. That's darn close to .4. Mystery solved.

 

[KineKilla]

Good call. I've been using the pool calculator but haven't noticed the part you mentioned. I'll give it another look, thanks!

 

[poolnoob.ca]

PH dropped to 6.8. My TA is slowly dropping now that the pH is rising from aeration.

I dont think thats how it works. Its the pH drop from adding acid that lowers the TA. The aeration simply raises the pH back up but doesnt affect the TA

 

[KineKilla]

So if my PH is dropping due to the addition of CYA then should I not start seeing my TA coming down as well? Do I need to let it sit at a low level somehow or just push it back up from 7 ?

 

[Richard320]

TA might be climbing from adding fill water. Or you could have static electricity on the bottle tip. That makes the drops smaller so it takes more drops to change colors and you get a falsely high reading. See the TA test notes in Extended Test Kit Directions.

 

[poolnoob.ca]

What was your TA when the pH was 7.4? Maybe it has already dropped down to the current 150. Anyway as richard said above, aeration wil raise the pH upwards without raising TA anymore

 

[KineKilla]

I did have to add a lot of water this spring to bring the level up from the winterized level. I'm going to continue to bring it down through aeration and PH reduction and hope for the best. Should work out OK since I still have CYA to add to get it up to acceptable levels which apparently brings my PH down.

How fast should it climb once the CYA is fully dissolved and decent aeration achieved?

My TA has actually gone up from 130 over the last week or two, not down to 150. Thus my confusion...my water is getting more acidic (PH dropping) yet my TA is going up instead of down. How is that possible?