Someone with a pair of 10 gallon tanks, and wanting something to do with them, could do some experimenting on "heavy root feeders". You could perhaps put ADA Aquasoil in one tank, and pool filter sand in the other. Fertilize both tank using the EI dosing tables, and use Excel or pressurized CO2. Use identical lights on the two tanks. Plant a couple of sword plants in both. And perhaps a couple of crypts.
My experience was with swords and crypts, as I recall. And, it was a 29 gallon tank, with high light and pressurized CO2. When I would remove a plant it would have an enormous, full tank root system. The swords would grow to full tank size in a few months. The crypts would fill the whole tank, getting higher and higher, in a few months. Blyxa japonica would fill the tank piling up on top of each other.