Hi
An idea I've tried for large messy fish is using a grate much like a false bottom terrarium . In my case was elevated around 4 inches off the bottom . One end was left open . Allows siphon or discharge hose to be moved around the "plenum " when cleaning . In coming water was added with varying pressure causing debris to float . This was picked up by a canister filter . you can cover the grate with fiberglass window screen or use gravel lage enough it won't pass through.. i had an auto water changer on the tank but wouldn't be necessary. Most debris free tank I've ever owned as well as never having to vacuum the gravel. Wouldn't use it on planted tanks with a substrate or small current stressed fish. Ideal for "rocky " type setups gary