Currently I have about 1/2 inch of gravel in my tank. I know a true amazonian biotype should have sand. I've never used it. What is better for a Silver Aro? do you vaccuum it like gravel, and run the same canister filter, biowheel, skimmer or does that change it??Does it affect water parameters? How would one introduce sand in an active aquarium after removing gravel.....???? I think you get idea here....input?