Loss of Appetite

UPDATE 8/9/2012
I know it must seem like I'm always correcting myself with these updates, but I'm documenting the learning experience and attempting to pass on knowledge as I learn it.  Many times it appears that I have understood the problem at the time, but as more information appears this changes on occation.  

A few days ago I found small red worms, and at first thought they were Camallanus, but it turned out to be Midge.  Midge is a great food for fish, and it was only after transferring my fish to the raft so that I could better care for them that I figured that out.   The fish have not shown the excitement they used to show when fed, and I wonder if this is because they were feeding on Midge worms, and have become spoiled.  Simple fish food must seem tasteless to them now, and I suspect this is the reason for their lack of appetite.

ORIGINAL POST:
For about six weeks my fish have not been eating as aggressively as they used to. 
They have been showing signs of breeding, and I attributed this to the loss of appetite.

But it was about the same time I added Dr Iron iron chelate. 
The iron made the water quite brown, and I also observed some algae on the walls of the tank, and in the water which I attributed to warmer weather. 
So the cloudy water did not concern me, and my assumption remains that iron chelate is not harmful to the fish, but it's definitely not to be dismissed.   
The Iron Chelate level has dropped from 0.5 ppm to 0.1 ppm over the past three weeks.  Today I bumped that up again with 60ml of Dr Iron .
 
Before the fish began to loose their appetite I began to allow the salt levels to become depleted in an effort to see what affect if any a 0.15% salt level has on plants.
I let the salt level drop to zero over the course of a couple months.   That experiment was trashed when a leak developed in my grow bed, and I had to remove all the media and plants. 
The bacteria took a small hit but I was able to preserve, and restore the bacteria within a few days by using a small wet/dry bio filter.
Two days ago I began to bring the salt levels back up since I have very few plants left in the grow bed to experiment with.  I'm now using this system for starting seeds and growing outdoors in my other system.

After bringing the salt up to only 0.9% the water cleared the fish began to eat better.
I'll continue to watch the fish to see if their appetite continues to improve, but since I have several variables going on I'm still trying to figure out what it is that caused the loss of appetite.   It might be simply salt levels, but I feel that there is more to it than that.  Maybe there was enough algae in the tank to keep them satisfied. I'm also  pretty sure they are also eating their young even though I have tried to provide a safe areas for the fry to escape into.

I added FE2 today, so I should be able to tell if this is the cause or not.  I'll update this post as I learn more.

UPDATE July 22, 2012 
After adding the FE2 on July 16 the water became dark again.   The fish seemed to feed a little less aggressively, but they did not ignore the food like before.  A week later they are eating better.   Dr Iron contains Phosphate 5%:  Potash (K2O) 8%;  Iron (Fe)  8%  so there are other ingredients beyond FE2 and it may be that this may be causing the fish to temporarily eat less.