The substrate in the lasar cory tank is play sand, you can get it at any of the hardware stores for like 2.50 a 40lb bag. The only problem with play sand is you have to rinse it a 100 times(just seems like) to get all the dust out and it will still cloud your tank for a day or two.
My favorite by far is pool filter sand, you can get it at any of the pool stores. Its clean already and all you have to do is dump it in your tank and fill with water. Thats what I have in the 55G loach tank.
With a sand tank Malaysian trumpet snails are a must to keep the sand loose though.
I really don't fertilize my plants, I just plant them and the fish do the rest

The bigger plants once in a while (about 2x a year) I put plant tabs under them. I think off-ice has given up on trying to convince me of a good fertizilation program and CO2

. If your really interested in learning about plant fertilization
www.plantgeek.net is the best place
to learn. Yell if I can help any more
Carol