Zedar, the description above pretty much covers it (no pun intended). I do very little at a time to avoid the pH and/or storm. Generally, I'll put maybe a 1/2 Tsp of powder into a small container, then use one of the old measuring syringes from one of my old test kits and add a small amount of water to the powder, and mix it up. I mix it as thick as I can, while keeping it wet enough to still be picked up into the syringe. I would say it's usually about the thickness of peanut butter. Then I turn off all water flow and manually apply the paste to the GSP. It looks like white snail poop all over the place, so I will then carefully and slowly rub it into the GSP, creating a mat of white paste. I wait at least 10 minutes with no flow, then turn on flow again, one powerhead at a time. Some of the kalk will always be washed away, and I just watch the corals to see where some lands. I don't bother syphoning off the paste again, though that doesn't sound like a bad idea at all. I prefer to keep the kalk in a thick layer, and it tends to solidify and become a permanent addition to the live rock.