I currently have 3 AQ 500's on my 125 gal. My fluval died. So I purchased an XP4. what are your thoughts on carbon, foam, ceramic etc. I have heard there is something better than charcoal? doesnt charcoal remove everything from your water even the good stuff. suggestions on what you use or what you would do I plan on having 2 AQ 500's and my xp 4. my fish load is in my signature. plus 3 sets of fry dashing in and out of the rocks