CSI?

[like2lean]

Happy New Year!! Thanks to this board I've got a good understanding of the chemistry now, but the CSI thing on the calculator has me confused. It seems most recommendations for CH are 250-350, my 2 mo old plaster is at 280. When I plug my readings in, it says I need to raise my CH to 450 to get the rec. CSI of -0.6......that seems to be high from I've read, what do you think?

fc-3
ta-80
ph-7.4
ch-280
cya-30
temp-50

 

[Richard320]

Check for a typo when you entered the data. I get CSI -.45 with your numbers, which is fine.

 

[chem geek]

Your pH should be rising with the relatively new plaster curing. You can target a pH of 7.7-7.8 given the colder water temps. Normally water will rise in pH as it gets colder anyway and this tends to keep the CSI fairly constant.