It should be alright but in mixes there can just be too many different things in it. With organic soil you get all organic ingredients, no extras. And as jetajockey asked, did you cap it. You have to cap your dirt of you will continue to get a mess whenever you plant, do WC's or anything. It should be capped with the Eco, sand, or whatever you wanted to use. When dirting a tank you put your dirt first, then your cap which should be about
1-1/2 inches so any loaches or others can't dig down to your soil. It also makes planting easier as your planting in your capped layer and not your dirt.