I have a 29 gallon planted tank. The substrate is aquarium gravel over peat
and some laterite for iron. The pH runs in the 6.5 range and the water is
SOFT SOFT SOFT. For lighting I have two power compact strips. So light is
not really much of a problem. The tank is stocked with small Amazon basin
fish (tetras and the like)

My question relates to fertilizing the plants. I have noticed that some
tend to grow ike weeds (Rotala indica for example) while others are barely
holding on (Amazon swords, and anubias). I have been using one of those
commercial "aquarium plant supplements" one adds to the water. But I have to
admit that I am not all that convinced that this stuff is all that
effective. Is root feeding better and, if so, what do you use? Would Jobe's
plant spikes work or are they full of phosphate? Anyone have any
suggestions?

Doug