Generally, slow release tablets or granular fertilizers with an analysis of 20-10-5, 5-10-5, 10-6-4, or 12-8-8 are all acceptable. Feed monthly for the best results. Tablet forms of fertilizer are the most convenient to use as they can be pushed into the soil. Granular forms of fertilizer can be wrapped in some type of biodegradable paper such as a coffee filter to make application easier. These can also be easily pushed into the soil. Cover the hole back up so the disintegrating fertilizer pellet will stay in the soil and not melt into the pond (feeding the algae not the lily.)