well my buddy cam over today and said his parents took down there 55gal goldfishtank lol (he said the put the gold fish in the TN river but anyways ive been wanting to get a assortment of fish for my 75gal display tank (35gal refug, 29 gal sump) but my lion and betta wipe out anything smaller than them so i want to here more of your lions den idea i have a 55 and a lion fish and marine betta to go in there.