i wouldn't do wet/dry, go with refugium. wet/dry becomes a bad thing after a while. the particles that build up over time in the balls becomes not good for the tank. you will have better results with a refugium with a sand bed of at least 6 inches (certain chemical reactions happen when oxygen levels are 0 - which takes about 6 inches of sand to achieve), 8 would be better, mine is closer to 10. put some chaeto and some small live rock pieces in there, maybe even some mangroves. a protien skimmer is something you want to look into as well. if you insist on using tap water instead of ro/di water then you will want a phosphate remover or you will have bad algea problems. i use ro/di water and still put a phos-reactor with phosphate removing media in it just as a precaution anyway. its small, and can hang off the side of the refugium. good luck!
