Most two bulb fixtures won't work with just one bulb - apparently the bulbs are wired in series. Why not sell that fixture and get a Coralife 2 bulb T5NO fixture, which would give you about the same amount of light, but with two bulbs, there would be less shading of plants. The possible problem you might have is that a 75 gallon tank is 18 inches front to back depth, and a single, or even double bulb fixture doesn't give very uniform lighting over the whole substrate.
You could dose the same fertilizers as with EI, but dose less and less often. Dosing once a week would work well. You can use as much CO2 as you wish, but lowering it a little would ease the stress on the fish, and do just as much good for the plants.
You could dose the same fertilizers as with EI, but dose less and less often. Dosing once a week would work well. You can use as much CO2 as you wish, but lowering it a little would ease the stress on the fish, and do just as much good for the plants.
