Questions about FC vs Bromine; CH, pH and TA

[sehaasch]

I've been reading the Pool School info and the various links that you have referred me to, but I'm a little bit of a slow learner. Here are several questions with regards to balancing the water in my spa.
1. Since I use bromine, do I need to test the FC levels? Or should I just focus on keeping the bromine levels where they should be and shock the spa once a week with bleach?
2. Since my CH is 300, is it okay for my pH to go down to 7.2?
3. My TA is usually 60, but has increased to 80. Is that a concern?
4. Is there a cheaper or more natural solution to soak my filter in? Or should I use the pool store brand?




260 gal. outdoor spa, cartridge filter, no ozonator,

 

[chem geek]

The test kits for chlorine and bromine test the same things -- they only differ in the units of measurement (the scale they show you). 1 ppm bromine = 2.25 ppm chlorine. So you can use either test kit. If you have a bromine test kit they use it. If you have a chlorine one, then divide your chlorine reading by 2.25 to get Total Bromine.

A high CH of 300 ppm in a spa can lead to scaling if the pH and/or TA get too high. So you can try and keep at least one of those two lower.

80 ppm TA could lead to a faster pH rise in a spa. If you add acid to keep the pH lower, the TA should drop over time. It shouldn't be increasing -- I wonder what you've been using that has had the TA increase.

See Cleaning a Cartridge Filter from the Miscellaneous section of the Pool School. The instructions for bromine would be the same as those shown for a chlorine pool/spa. I don't know about natural, but you can get TSP or dishwasher detergent from sources other than a pool/spa store.