Lowering a high water level to reduce plant height isn't a bad idea. If the roots are dependent on that water, meaning that they are growing in it, and you have mixed fert in the water, you have to be careful because usually as a plant grows you use more fert and perhaps more water due to uptake and evaporation. I'm guessing that some light will get in the aquarium, which will cause algae to grow but it might not be too bad. Just never heard of growing like this. You want your water to be completely hidden from light to avoid algae, but you might be able to make it work. Frankly, I think it might be better to spend a few bucks on a DWC bucket. Are you planning on using fert poop as fert? Why not just grow in soil?
polishpollack Reviewed by polishpollack on . Marriage of aquaponics and hydroponics in enclosed aquarium I have a 40 gallon aquarium with a large back pack filter, underwater heater, 20 white cloud minnows, and an airstone. I also have a 36 inch light fixture with four T5 HO Floursecent tubes; two of the tubes are 10,000k daylight, and the other two are actinic (blue). All four tubes are rated at 39 Watts... Would I be successfull growing a small plant if I were to remove the filter media from the back pack filter of my aquarium , lower the water level 4-5 inches, cover the outer walls with Rating: 5