Re:Growth has stopped

     >About a month ago, growth stopped and now many of the leaves are 
     >transparent.  Nothing has changed that I am aware of - weekly water 
     >changes 10-20%, lights on a timer 12H/day, 2 40W bulbs 1 full spectrum and 
     >1 warm spectrum (they are about 5 mo. old), temp 78F, pH 7.2, inconsistent 
     >addition of FerroVit, regular gravel no addition to substrate.  Any 
     >suggestions to stop the trend and get back to growth and runners?
     It sounds like your plants have stopped growing because they are 
     CO2-limited.  You can easily (and cheaply) add CO2 by using the sugar-yeast 
     method, described in the Krib and in many APD postings.  
     The transparent leaves may be due to a potassium deficiency.  I suggest 
     using PMDD--this will end the yellow leaf problem, and will cure your hair 
     algae problem as well.  The PMDD paper and recipie is also contained in the 
     Krib, under "Fertilizers".