Alright so i currently have a emperor 400 on my 75 gal and i would like my water to be cleaner then it is. I just took down my two 20 gallons and i have 2 aqua clear filters that i am not using. One is for a 20 gal, the other is for a 30 gal. I am short on money so instead of buying another big filter for my 75 i wanted to put these two to good use. But when i try to hang them on the back of the 75 they wont fit....any ideas? (i know there not made to fit a 75, but is there a way i can use them with my 75?)