yet another problem 8(

	Several weeks ago I posted about my iron overdose, algea bloom,
green water, and a few dead fish.  Well, the angels (2) died as did few of
the cardinals.  All six of my ottos as well as two clown plecos are doing
fine tho.  I've done numerous water changes (it's been about 2 weeks
since I "nuked" it with the fertilizer) and the tank is nearly see
through now (depth wise anyways).  After a 40% water change, the tank is
clear.  Several hours later, however, the water begins to cloud and it
keeps getting worse as time passes.  The plants are doing ok as are the
fish.  My substrate consists of about .5" of peat moss covered by about
2.5-3" of sand.  Could something have gone wrong with the substrate
causing the above cloudy conditions?  the tank has been set up for about
2.5 to 3 months and it's been really clear until I added the new iron
intensive fertilizer.  Current chemistry: Ammonia and Nitrite 0, Ph 6.8 ,
Kh ~3 , Fe 0.25 , temp 82F , 80W(triton, vita-lite).  I was considering
removing the substrate and  getting laterite with fine gravel.  Any help
with these reccuring "clouds" and their possible causes would be greatly