Calcium Hardness Recommendations

[DougS78]

I appreciate this thread as I've been having the same questions on CH. I am struggling to know of what I have is good or if things need adjusted. To complicate matters even further I am uncertain how to read the CH test properly. Is it when it goes from red to purple or do I read it when it goes to a true blue color??

Today's readings (~25k gallon, hydrazzo plaster)

Ph = 7.8
TA = 160
CH = 250 (turns purple)
FC = 1.2
CYA = <30

These numbers have been very steady since we got it up and running late last fall. The PH tends to creep up to 8.0+ (highest reading) and I periodically add acid to drop it.

are these ok and if not what should I shoot for?

 

[Texas Splash]

Keep going. It should go from an off-red, to purple, then finally a baby blue.

How does your water look? Your FC is much too low, and your CYA could use another 10-20 ppm as we get closer to warmer weather.

 

[DougS78]

Thanks for the input. In that case my CH is closer to 350. That is the point it gets to a true blue.

Water looks perfect. I'm in the process of getting CYA up. Test tomorrow should be above 30 I hope. I've been adding liquid chlorine daily in the meantime.