New tank, recommendations welcome

[thirst4theworst]

I have a Via Aqua 680 aquarium tank, 18 gallon. It is just the tank with about 17 gallons in it. I have a nova extreme t5 settup with the lunar light. For filtration I have a Marineland penguin 350 dual biowheel and a smal nano powerhead to add to the tank flow. I have about 15 to 20 pounds ( I forget) of LR and about 3 inches of the " live" sand you can buy at a LFS. Current inhabitants are 18-20 trochus snails, 17-19 small blue legged hermits, an arrow crab, a banded reef shrimp, 2 peppermint shrimp, 2 nassarius snail ( maybe the super tongans), a 1 inch round sea urchin( wild caught), some type of flamed scallop (also wild caught) and one small tomato clown. I am looking to either kick out a few current residence, NOT KILL (most likely give to a friend with a much large settup), and maybe start adding soft corals or a powder blue? any thoughts, opinions, or changes are welcomed. just please tell me why, as so I can learn and not just do what someone tells me. Or ask me whatever you would like to know, either way. This forum has been a big help to me so far so i am just going to see where this takes me. Thanks.

[Loverotties]

To small for a Powder Blue and I'd buy a skimmer if I was you.

[crvz]

welcome to TRT! Everything sounds pretty good so far, but you'll want to stay away from surgeonfish (or any large fish, for that matter). With only 18 gallons, you just don't have the space needed for a fish that size. Recommended size for tangs probably start in the 90 gallon range, but most species need something in the 150 or more to be housed comfortably for any amount of time. The swimming space available in an 18 gallon tank just doesnt cut it, unfortunately.

Otherwise, some soft corals may be a good next step! You may consider loosing a few of the clean-up critters, but in general they're no real concern.