Well ill play this one off of liveaquaria. You wont be able to keep anything in a 5g due to them requiring a 10g or more. Have you tried anything in a 5g? If not then your input is not needed. I didnt ask for help. I just simply posted my tank. You say a couple of trimma gobies but yet they also require a 10g. That would cause the fish to grow improperly and cause damage as mattyfelts says. Maybe you both should consult with each other and get both of your opinions together and post together. Please research the min requirements before telling me to add a fish to my tank. Its not like im adding a naso tang to a 40g. If neither of you are marine biologist then your input isnt needed.