Over flow ?

[paintballingajs]

Okay so I have a very large over flow on my 150 about 12-15 gallons maybe more... SO here is my idea, Fill it with bio media and make some kind of pre filter that will rest on top of bio media to collect all the junk. Second question if this is a good idea what is a cheap bio media i should fill it with...

 

[nfored]

I have seen this done, I would personally use seachem biomatrix since its meant to be ran submerged, and then the blue filter mat.