Smorgasbord

No problem, your answer was very helpful.

Thanks, Osric! This really answers my question. Do you know if there's still a way to measure the amount of chloramines?

They say that the ideal range for ph is 7.4-7.6. For calcium hardness it's 150-250 for a hot tub. The way I understand it, the watergram is useful to balance things further after they are within those ranges. So yes, 0 is the best balance, but if you raise your CH to 150 you could lower your ph to the 7.4-7.6 and keep the water balanced. Now, from what I understood, if the calcium hardness is low your water will have a tendency of dissolving concrete, plaster etc. Depending on the making of your hot tub, this could lead to damage over a long time, so that's the main reason you might want to increase it. All this I've learned from reading the little Taylor booklet, so take it with a grain of salt.

First post on this forum, so let me just briefly say that I'm really grateful that this exists. You guys are awesome! It was a real struggle to find reliable information before finding this forum. Now, as I'm starting out, I made a rookie mistake. I currently use bromine in my hot tub, and would like to keep it that way. However, I bought the test kit Taylor k-2006, which is meant for chlorine. My main question: do I really need to buy another test kit for Bromine now? If you can help, I'd like to understand the difference between the FAS-DPD test for chlorine and for bromine. Taylor names the pure FAS-DPD tests K-1515-A,C for chlorine and K-1517-A,C for bromine. Different names; does that mean they are different chemicals? If I use my current chlorine test with the water containing bromine, what is it measuring? Does it really measure only the chlorine (free and combined) in the water? Or does it measure a combination of bromine and chlorine? The readings I get certainly seem high for just purely chlorine. Many thanks!