So I've got approx 19l of Oliver Knott soil in my tank. However I'm getting a bigger tank and need more substrate. I can't find Oliver Knott soil 10l anymore and I really don't know what other substrate I could use. I was wondering if I bought aquaclay pellets would they work as a bottom layer and I put the Oliver Knott soil on top? Im from Europe so I don't have as open a selection. WHAT SHOULD I DO?!