I have been keeping freshwater for a while and currently have an empty 29 gallon tank. I would like to try my hand at a few small saltwater fish. I have done quite a bit of research but I am having trouble coming up with a definite answer about filtration. I have read everything from wet/dry is the only way to go, to you should use a filter for only mechanical and use live rock and sand for the biological. Keeping in mind that I am only setting up a 29 gallon tank, what are my best options. I have thought about putting a larger penguin on the tank, possibly even a 350 if necessary. Would this be the right move or not? I have also seen some info on turning a HOB filter into a refugium. Is this practical or even possible with a black cased HOB or is does it have to be done with a clear (Hagen)?