I have used it for about a year now and it has worked well for me. I do have to state the reason I got it, I am not here much during the summer and I can't take care of the tank as much as needed. Last year I had an algae bloom that destroyed my tank so I decided to spend the money and get the mud and this year the tank still looks good and there is very little bad algae growth at all. The coralline algae is still thriving and I have been able to keep pulsing zenia's, blasto's, leathers, and zoa's all alive without adding any more chemicals to the tank. The only thing I add is clean water and food. I know I am in the minority but I don't test my water so I can't answer any of those questions, sorry.
If any one else has any questions let me know.
Thanks,
Matt