thanks for the advice everyone!
I took some water quality measurements this morning...Amm: 0, Nitrites: 0, and Phosphates: 0. While nitrates are around 5 ppm, although the color didn't match exactly to any of the choices...it was closest to that.
I did look into additives but none of them seemed promising esp. at the price. 44 bucks for something I didn't even know would work! So, now that I have your advice I'm really glad I didn't try it! I'll look into the crocea clams...neat that I'll get good water and a neat animal out of an investment like that. However I'm unsure if we'll have high enough lighting for a clam with t5s...could he sit closer to the top of the tank if secured on a rock?
I've been looking into the sump refuge sites ya gave me...although he didn't have any mega sumps...so I'm going to look into them on their own. I didn't choose this sump, but I'm going to have to make due anyway.