Warr. Sorry that I haven't replied to your question. I take a small amount about the tip of a teaspoon or if you have a TM test kit with one of those tiny spoons, use half of that for a 700 litre tank. I mix it with some tank water and then go about cleaning my tank, blasting the rocks with a powerhead, turning the substrate to kick the dirt up. I then add it slowly to the back of my sump so it has lots of time to mix with water and oxidise the DOC's so it's neutralised before it enters the display. I also get my skimmer to skim a bit wet for a while. Potasium permangeanate also improves the redox of the tank and I haven't had any problems with my SPS's, LPS's and softies in my display tank. I do this once a week as I'm sure too often can be bad.