Increase Calcium Hardness?

Gtoledanes

Member
May 29, 2020
6
Houston
My test results this morning.

FC 1
TC 1.5
CYA 40
PH 7.8
CH 225
TA 80

I’ve been keeping my pH around 7.3 to 7.5 every other day as we use the pool

I Slammed the pool about 9 days ago due to heavy rains up to TC of 14 and have been keeping the levels around 5-7 when we swim.

I’ll probably adjust the pool’s pH to 7.5 today and Get the FC up to a little above 9 or 10 today since a saw a little bit of green.

I have noticed that my CH has been steadily dropping and have retested each time to account for error since I made the switch from the calcium hypo to the liquid chlorine. Any advice on how to increase hardness or anything else I should watch out for on my numbers?

Thanks and Happy 4th
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,637
Laughlin, NV
I would be more concerned with the very low FC. Add chlorine now.

You followed the SLAM Process through to completion? If you have algae now, you need to SLAM again.

You do know you have to maintain FC in target range all the time, right? Not just when you want to swim.

If this is a plaster pool (please complete your signature), go back to using calcium hypochlorite to add calcium. You can take your CH to 350 ppm without issue with the rain you get.
 

Gtoledanes

Member
May 29, 2020
6
Houston
My pool is plaster and tile.

Yes I was planning to SLAM again today. The last time I did take it to completion and maintained the SLAM levels until things were clear and let the chlorine levels go down on their own. The algae I was seeing was in the raised spa area and don’t really see anything within the pool itself.

I try to check the levels every day to every other day and adjust as needed. I guess it seems like it’s when we swim since we’re in it almost every day to every other day.

As far as the pH goes do I have to be aggressively keeping levels low like 7.3 range in regards to calcium levels to keep scaling from occurring? I’ve been following the CSI in the pool math app which is why I’ve been keeping the pH lower than what’s in range.

Thanks for the advice!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,637
Laughlin, NV
With your data shown above you are no where near scaling tendency. You should lower your pH prior to SLAM, but otherwise anywhere in the 7's is fine.

Your spa water is still part of the pool. Does not matter where the algae is, if you can see algae, your pool is overwhelmed with algal spores.

Your pool water FC should NEVER fall below minimum as shown on FC/CYA Chart
 
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