Well first thanks for the help with the pacus they are doing fine know and eating everything thing in sight. Included my plants. It seems impossible to keep the cichlids in there due to the ph differences. So I decide on taking out the Malawi cichlids and put them in there own tank. I purchased a 29 gal recently and was wondering what the best substrate to use is. I'm not sure as they are diggers should they have sand or small rocks. What's the best to use they would not injure them. Or is sand to small for them. Seems they might be inclined to ingest some.