Hi I have a planted tank with eco complete substrate. But no matter what i do to arrange the substrate to make it look nice, it always returns to being dead flat in no time. Any advice on maintaining troughs and gullys in planted tanks?
You can use driftwood, rocks, plants, etc. as barriers to hold the gravel. But it has a tendency to eventually level itself out and create a "stair-step" look more than a "rolling hills and valleys" look.
You could get pieces of glass cut a various lengths/heights. Then use aquarium epoxy (bonds underwater and is fish safe), to fix the glass to the bottom of the tank. Fill in the areas with enough gravel (or use styrofoam as a lift), to cover the glass pieces.