k1 and lava rock are the bio filter,, how do you plan on setting up the wool? i ask about the drain because i have mine set up the same way, lost power and even with the 1 inch drain it could not handle all that water at once and the barrels over flowed. my barrels are outside so i planned on if that happened it wouldnt be a big deal. another point is that when the barrels overflowed most of my k1 came out also so i am in the process of building some sort of net on top to prevent this from happening again... just think, you have (1) 1 inch drain but you will have (3) 1 in pipes feeding that barrel.. not knocking you just trying to help with the issues i have noticed on my build. (the link is in my sig.) btw here is my filter set up.
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