i was on the aquariumplants.com website and was looking at their 5 gallon tank substrate. i was wondering if anyone has used it and had good results. but my main question is if i can keep fish in in the tank with this substrate since it is supposed to be iron rich for the plants. its also the cheapest black substrate i could find for my 55 gallon tank. any help would be much appreciated :nilly::screwy: