Hate to resurrect an old thread, but I am new and my search for this topic came up with this discussion. I have the same issue, but I'm using bromine tablets instead of chlorine. PH levels were a bit high so just waiting for that to settle. Also shocked it earlier this week to try and help.
We just got the tub 2 weeks ago and have been trying to learn! Any suggestions for getting rid of the slime in a bromine-based tub would be greatly appreciated!!