Can some one she'd some light

[duanes]

Since your ID says reefman, I might assume (if) you have a old protein skimmer or two laying around.
I use fractionation on freshwater tanks (albeit it takes much higher flow to fractionate than in salt water due to density) but until the nitrates your tank is under control, you may want to use the unit to remove nitrate precursors. (A caveat) Many commercial units made for salt tanks, are too wimpy for fresh water
My DIY units always work best in spring on my ponds when nitrate precursors and organic carbon are the highest.

 

[reefman]

Since your ID says reefman, I might assume (if) you have a old protein skimmer or two laying around.
I use fractionation on freshwater tanks (albeit it takes much higher flow to fractionate than in salt water due to density) but until the nitrates your tank is under control, you may want to use the unit to remove nitrate precursors. (A caveat) Many commercial units made for salt tanks, are too wimpy for fresh water
My DIY units always work best in spring on my ponds when nitrate precursors and organic carbon are the highest.

I havnt had salt for a while but a protien skimmers are simple to build. I'll give it a try

 

[Malte81]

Could this be a ich problem?
It looks like white spots disease.

 

[reefman]

It's not ich