The one big change in the method to feed a beautiful aquarium plant is the use of potting vermiculite in the lower substrate layer with the soil, rather than sand. I pushed pieces of the pond lily tablets into the substrate (both the loam and the lily tabs were suggested by TN). I attribute this success to: the fine soil fraction at the bottom which provides high cation exchange capacity, intimate root contact, and holds the fertilizer nutrients in the soil; the pond lily fertilizer tablets which contain nitrogen (both soluble and insoluble), phosphates, potash, iron, and other stuff listed below; and the soft vermiculite layer which makes root penetration easy (and may even help curtail metal ion toxicity problems often present in freshly submerged soils). Some of my tanks are algae-free (none visible whatsoever), but the higher light tanks still have some algae (though not a big problem). I have noticed that fine Crypt roots stay in the upper layer, and grow just fine there.)