I have a 29 gallon as well, and I have 2 false perc clowns (babies) a pajama cardinal, and 2 sand sifting blennies. That's 5 fish in a 29. My bioload isn't out of wack, and my tank is extremely clean. So I don't see why not about adding 2 clowns. On top of all them I have a coral banded shrimp, Atlantic Anemone, hairy mushroom coral, neon green mushroom coral, 3 feather Dusters, 15 hermit crabs, and 8 turbo snails. My sump runs at about 350 gah. If you take the right steps you can put almost anything in your tank. The only thing is as soon as my clown get to mature size I'll have to move both or 1 to my 75 tank. But till than I'm keeping them together.