Skimmate Consistency

So I have an aquamaxx hob skimmer, which has awesome reviews.. AquaMaxx HOB-1 Hang-On-Back Protein Skimmer

I had it set as high as it goes when I first got it, and I got dark thick skimmate. I then moved it down as necessary. It was only like that for a few weeks though, now its pretty clear liquidy green skimmate. Sounds appetizing I know. I haven't changed anything besides emptying it and repriming it once or twice.

Yes I know the drill:
I have a midas blenny, a clown, a melanurus wrasse, a mandarin, and a YWG in my 37g DT with a 10g sump/fuge. Plus a little LPS, lots of SPS, and a bunch of zoas. This really isn't a huge bioload, is it possible that there just isn't enough to skim? The dark skimmate may be the result of waiting over a month to replace my broken skimmer.
As of a week ago (this has been going on longer than a week):
pH 8.0
Ca: 420
Alk: 7
Mag: Around 1400 I think
NO3: 0
NO2:0
NH3: 0
Phos: unreliable/unreadable test kit but low algae growth

 

I have the same unit on my 55g, works really good for me, it was fussy when I first started it, but it has calmed down and produces a whole cup of nasty skimmate every 5 days.

 

Whats your bioload like?

 

Bi color blenny, clown goby, small yellow tang, ocellaris clown, six line wrasse, toadstool, large colony of zoas, and a giant polyp Duncan with four heads.

 

There's a picture of it in the show your skimmate thread