Hi people... i've read the discussion on water column dosing vs substrate dosing. But i'm just curious what difference would it make. therefore i've bought some empty capsules and stuffed some KNO3 and KH2PO4 in, and then inserted it in a small portion of my tank with hair grass... (foreground, left) actually something is strange in my aquarium as the half left portion of the hair grass is growing too slowly, some not green, while the half right side is taking off nicely, growing more compact each day. it is a 1.5ft small tank, and diffuser is at the left side. light is even on the left and right, HOB at the left, thus blowing the CO2 bubbles down at the left front side first. so logically the left part should grow better. So i'm trying to see if some localised substrate boost will help... (if the whole patch looks bad, i would have add more ferts into the water as a whole) i just got my dry ferts (KNO3, KH2PO4), and have not yet have a consistent dosing regiment. I'm throwing in small pinch of the ferts every 2 or 3 days. Generally there is no algae problem except the tiny green spot that i have on the glass. Any comments on the experiment?