No tangs in a 30 g. Add more l/r if you can. Stick to dwarf angels, clownfish, six line wrasse, flamehawk,royal gramma, chromis, type fish. If I were stocking, I'd add a flamehawk, yellow stripe maroon clown, and bi-color angel or royal gramma. This is my preference of course. DON"T ADD THEM ALL AT ONCE! Slowly is the key, one at a time with 7-10 day intervals. I'm assuming tank is fully cycled. If you are going to add l/r, do it slowly first then add fish. Good luck.