They sent it with rockwool so i did some in that and then i was also starting my veggie garden so i had the jiffy seed starter kit that had the little peat pucks and started some seeds in that. When i transfered the plants that started in the pucks i just rinsed the soil off came off pretty easily from what i remember, and i normally change the water every two weeks just because it made me feel better so i never really ran into a problem with a whole lot of stuff floating in the water. We shall see soon though one of my seeds poped out of the shell last nite so hopefully in about a week i will be able to move it to hydro. There is one more that is close to coming out of the shell and two that are taking thier time. I am hoping that i can have my seeds and my clones start at the same time. I need get some more ph stuff so when i do i will soak the cubes (i have the small ones) and try seeds in those.