I've got 3 small tanks ( Two 10 Gallons and a 20 Gallon Long) with low light (1.5 to 2 WPG of NO T12s), no CO2 growing Ludwigia Repens, 4 various species of Crypts, Didiplis Diandra, Rotala Indica, HC, Hygrophila Difformis and Alternathera Reneicki with no algae. I do use Excel and do weekly 30-50% water changes and dose macros once a week. Growth is slow but steady. The 20Long actually looks as good as my High light, pressurized CO2 30 long.
Mike