Hi. I have a 21 person hot tub, not located near any grass, that is always green. The staff in charge of keepign the pool and tub maintained says the Ph levels and chemicals are all fine. But isn't the same blue color we once had when it professionally installed last year. It's located on a roof.
I was wondering what I should be telling them to look for to keep the hot water blue for a longer period of time. Sometimes, something they do changes it back to blue. But it only lasts for about 2 to 3 days then returns to its original color. If the Ph levels are fine, and from how quick it goes from blue to green, I was wondering what the cause was or how to keep it in nice condition for longer.
Here is a pic of the example.