[Myka]

I hope you plan to remove all those Tangs. There is no tang in the world that will be happy in a 50g tank when it's any bigger than 2-3". I don't know how big they are right now, but they are pooping machines, so they could be contributing a lot to your water clarity issue. What are your nitrates at?

You have significantly lowered the effectiveness of your PhosBan Reactor by plumbing it into the Mag 5. The flow through the PBR should only be about 150 gph. It takes time for the media to suck the phosphate out. I don't think carbon is your issue.

The "felt bag" that you are using...is it a "100 micron filter sock"?

Your sump looks really young...how old is your setup? You only have 4.5x turnover through your sump. Sorry to say you should have bought a bigger pump. You should be looking at anywhere from 6-10x turnover. I personally prefer 6-7x turnover, and think anything more than that is a waste of electricity...unless it's a FO or FOWLR tank. This means you need something more in the range of 425-525 gph at 4' head. Yours is only producing 310 gph at 4' head. I'm thinking this may be a significant factor in your problem since the water isn't going through the sump fast enough for the filter bag and skimmer to clean it well.

Another thought is your skimmer. I have no idea what kind that is...looks like a Euro-Reef knockoff of some sort. Skimmers are worth their weight in gold, and you should NEVER skimp on the cost of a skimmer. This may also be a contributing factor to your unclear water.