I just re-did my 75 with AS and PS, Knowing what was suggested the first week and a half or so I was doing about 3x water changes dosing only K after each WC. Its been set up for a few weeks now and WC's are down to 1-2 a week, plants have slowly started to show new growth, and I have been testing the water to see where I was at. Basically it appeared that there was a fair amount of N being leached into the water colum, but little to no P.
For me I decided to rely pretty heavy on substrate ferts, I am using tropica root tabs, basically shooting to have the bulk of nutrients supplied and maintained via the substrate. But in addition to this to keep water colum levels stable, and in an effort to not exhauste the substrate to quickly, I am doing lean daily doseing of the water colum.... around 1-1.5 ppm N and about .6 ppm P, also a fair amount of K are being dosed daily.
That being said it is working for me so far.... but choose what fits for you best, If you had luck in the past using EI, and adding an excess of ferts several times a week, and you were pleased with the way it worked, then by all means do it with your new set up. Though Im not really sure you would need such excess with such a nutrient substrate
