This may sound like a stupid question
but you know what they say...the only stupid question is one that is not asked. Hopefully that still applies after I ask this:
I ordered a Pangea Background for my tank. I will be leaving space for filter intake, heater, maybe some bioballs, and possibly an airstone (depending on the replies from my other thread). I will be using a sand (pool filter sand) substrate. I would like to benefit from the advantages of using flourite, or leterite, or eco-complete. What I don't want to do is mix the sand with those because of a loss of color in the sand. I have heard that some of these clump up, leaving patchy looking type substrate--don't want that.
What I was thinking, was can I put one of the above behind the background? Does the stuff have to be in the substrate for it to be released to the plants, or does it get released based on water parameters? Sorry if this really sounds stupid.