Hi, sorry to have to bother you again. Early May, I have refilled my pool after a black algae affair.
And I have then switched to salt.
I have filled with borehole water that had a very high TA (300+).
I have followed the recommended procedure to lower TA: aerating to lower PH and adding MA.
This worked quit well. After adding a lot of MA (38L) the TA was down to 175.
After that I have not added any more MA manually, but the salt water system has an automatic PH- pump (and a PH sensor) that pumps MA.
I have set the automatic PH level to 7.3 and that level was kept well. However, the MA consumption by the automatic pump was still very high. A 20L can was gone in 4 weeks or so.
Then I went away for 3.5 weeks, and someone kept an eye on the pool. Then the MA consumption suddenly dropped very much. From about 5 L per week to almost nothing.
When I came back, I have measured the TA again, and it is zero (with my Lovibond meter and tablets). I have measured twice.
It looks as if the MA has killed all the TA. I feel a bit silly now. First the TA was way to high, and I did go through a lot of trouble to lower it, and now it seems to be all gone?
The PH is okay, 7.2 of 7.3 when I measure it.
So, should I now start adding baking soda? Will that then also be consumed by the MA that the automatic pump adds? Will I constantly have to add baking soda to compensate for what the MA eats? What is the problem with the low TA?
Other parameters: FC = 3.4, TC = 4.3, CA = 250, CYA = 25
Another thing is that I have not found backing soda for a reasonable price here in Portugal.
Thanks!
And I have then switched to salt.
I have filled with borehole water that had a very high TA (300+).
I have followed the recommended procedure to lower TA: aerating to lower PH and adding MA.
This worked quit well. After adding a lot of MA (38L) the TA was down to 175.
After that I have not added any more MA manually, but the salt water system has an automatic PH- pump (and a PH sensor) that pumps MA.
I have set the automatic PH level to 7.3 and that level was kept well. However, the MA consumption by the automatic pump was still very high. A 20L can was gone in 4 weeks or so.
Then I went away for 3.5 weeks, and someone kept an eye on the pool. Then the MA consumption suddenly dropped very much. From about 5 L per week to almost nothing.
When I came back, I have measured the TA again, and it is zero (with my Lovibond meter and tablets). I have measured twice.
It looks as if the MA has killed all the TA. I feel a bit silly now. First the TA was way to high, and I did go through a lot of trouble to lower it, and now it seems to be all gone?
The PH is okay, 7.2 of 7.3 when I measure it.
So, should I now start adding baking soda? Will that then also be consumed by the MA that the automatic pump adds? Will I constantly have to add baking soda to compensate for what the MA eats? What is the problem with the low TA?
Other parameters: FC = 3.4, TC = 4.3, CA = 250, CYA = 25
Another thing is that I have not found backing soda for a reasonable price here in Portugal.
Thanks!