All I have right now to fertilize my waterlilies is Jobe's tomato spikes. I've never used them before. If my containers are 7 gallon containers (about 18" across and 7" deep), should I use 2-3 per container about every month, or is that too much? That's how many of the pond tabs I usually use, but I don't know how to compare them.

I think I need to order some pond tabs in bulk, since I go through one of those smaller bottles of pond tabs just for one fertilization.

Thanks!