more natural
remove colored gravel & any seashells (remove all sunken ships & skulls)Now get some Takahashi Amano books 4 inspiration .Pick out some flourite & mix with daRK brown un coloured med sized gravel & mix with some black smaller or similar sized black gravel.find lots of heavy hard sinkwood use a piece of wood to partition the gravel near middle for a 2 level effect & fill in one side with gravel .(a large piece of caverock or sinkwood with balance the ofset gravel) .research planted aquaria