Hi all i have a nano tank that is 60x30x45. the water is slightly brackish and there is a large piece of driftwood with some twigs and large rocks in it. the fish that are currently inside it are 3 bumblebee gobies, a knight goby (that keeps hiding) and a syncrossus hymenophysa (loach). Are there any other fish that u could suggest for this tank because it looks kind of empty now. As well as that, the wood keeps releasing tannins and the water looks like its been mixed with soap? Anyways, i'd be thankful for any suggestions.