CH in Fiberglass Pool

[woodjasonr]

I put a fiberglass pool in last fall and am getting it ready for the season (didn't close it, so it's just been a matter of balancing chem). Did a no-drain water replacement two weeks ago to bring CYA down from 90 to 60 (success!). Current numbers below using Taylor 2006 kit.

Question: Do I need to bring CH up, or is it fine where it is? Pool is Barrier Reef. They recommend 200-400ppm. TFP crossover is therefore 250-400. I'm inclined to either bring it up to 200 or even leave it at the current level of 130 for fear of inducing scale like I've read quite a bit about here on the forum (if it ain't broke...). The manufacturer suggests a pH of no more than 7.4 and CH on the lower end to prevent calcium scale. What would you do?

 

[Rancho Cost-a-Lotta]

Welcome to TFP. Sounds like you're off to a great start with a good test kit. 

A CH of 200 is good by our standards and also keeps you in check with the manufacturer's standards. Depending on the hardness of your fill water, your CH level will likely rise with evaporation.

 

[woodjasonr]

Welcome to TFP. Sounds like you're off to a great start with a good test kit. 

A CH of 200 is good by our standards and also keeps you in check with the manufacturer's standards. Depending on the hardness of your fill water, your CH level will likely rise with evaporation.

Thanks. I need to test my fresh water. I've always heard/assumed that we have hard water in my part of the country, but my observations with the pool would indicate it isn't that hard.

Anyone with a fiberglass pool have any lessons learned re: CH in a fiberglass pool? Is it better to err on the lower side of the recommended range to prevent scaling, or am I overthinking it? Again, at a present level of 130, I'm not seeing any adverse issues and don't want to create a problem by adding calcium.