The only kind of regular gravel you'll have a hard time with is the course gravel. It will be very difficult to get plants to root in those stones. The finer the gravel, the better the roots.
The Jobes sticks you want have a very low phophate number (the second in the standard N-P-K rating) so the houseplant one at 13-4-5 is pretty good. Some have found a "fern" version with even less phosphate, so if you can find that one, it would be better. Just shove one half stick underneath each large root feeder (sword, crypt, etc) and don't touch the plant or substrate around that plant for a month or two.
- Sam P -
plantedtanker in limbo - all tanks currently in storage