My 125g has 2 XP3's + ac110 on it currently. I'm looking at moving an xp3 or the ac110 off it for a new 75g side project and have ordered an fx6 to be here friday. I've got 500ml of purigen + 4Liter of pond matrix as well. How much media will the fx6 be able to hold as far as the extra stuff goes? I got 2 of the seachem bags as well to split the purigen between.