I am planning on using 3 2L bottles for the 135gal, with two glass diffusers (one on each end of the tank).
The current plants we have in the tank are Java Fern, Anubias nana, Cryptocoryne petchii, 2 medium and 1 large (the leaves of the large reach to within 3" of the top of the tank) Echinodorus "Rubin", and 1 VERY large (diameter of leaves approximately 3", with total length reaching to the very top of the 24" deep tank) Echinodorus 'Rose'. I have been noticing some of the leaves of the Echinodorus "Rubin" turning transparent, which I will assume is from lack of iron. I have been dosing liquid ferts in the past, but as I have just recently added a large number of crypts and will soon be adding even more plants, nutrients will definitely be lacking.
Since you mention the amount of phosphorous may be too high for my tank, what level would you recommend?