makes a great cap (assuming you mean with dirt/soil). no real benefits nutrient-wise for the plants but it is great to plant in. very heavy and consistent so it holds plants down really well. if you have never used it then I recommend you try it. it's only like $8/50lb
nothing to worry about. just rinse it out in some large buckets before you put it in the tank. it comes pretty dusty.
nothing to worry about. just rinse it out in some large buckets before you put it in the tank. it comes pretty dusty.