If you're going to have 2 fish and corals in a 75, your filtration from your rocks & sand will most likely keep you set for the duration of the tank.
A siphon overflow works very well. E-shoppes has a wonderful overflow box, if you want to set up a refugium. My 75 gallon was up with 100 lb of live rock and sand bottom. Had 2 clowns and a full grown kole tang in it, and my nitrates were 0 and phosphates were barely detectable until I started dumping in nitrates. I still after about 8 months have no detectable nitrates unless I put them there myself.
Don't get overwhelmed, don't over filter your tank, and definitely don't spend any money on equipment you don't need. Save that $$$ for some sweet torches.
A siphon overflow works very well. E-shoppes has a wonderful overflow box, if you want to set up a refugium. My 75 gallon was up with 100 lb of live rock and sand bottom. Had 2 clowns and a full grown kole tang in it, and my nitrates were 0 and phosphates were barely detectable until I started dumping in nitrates. I still after about 8 months have no detectable nitrates unless I put them there myself.
Don't get overwhelmed, don't over filter your tank, and definitely don't spend any money on equipment you don't need. Save that $$$ for some sweet torches.