tom, i have a 75 gal tank that is having a few issues. first of all i began having good luck by following your dosing advise but then i decided to put a nice piece of driftwood in the tank. in order to make room for the lumber i removed two large crypts and moved sag to back of tank. the tank has been set up since sept 03. 100% flourite, 220 watts ah supply lighting,and press. co2. using greenhouse grade fertilizer and seachem iron. thats when problems began. green dust algea and small amount of black on sag leaves. also put three pieces of water sprite in tank and they don't look so good. tank has three large swords, large crypt, and sag. lamotte co2 test kit shows into the lower forties. after about five hours of lighting tank looks like fiz factory.plenty of livesock also. could i have opened a can of worms when i restructured tank? i need your advice . could i have a new dosage plan of attack. 
thanks, cornhusker
thanks, cornhusker