Here's what I have for the filter setup so far. Am I correct in assuming that entire second tank does nothing more than hold the pump and the heater(s).


What's the deal with filter socks? Do I really need a special bag holder like this thing?

I assumed I could just attach the filter socks to the pvc by drawstrings or rubber bands, but it looks like they all have 4" or 7" fixed openings. Is there an easy way to use them?
What are some other options for mechanical filtration with this setup?


What's the deal with filter socks? Do I really need a special bag holder like this thing?

I assumed I could just attach the filter socks to the pvc by drawstrings or rubber bands, but it looks like they all have 4" or 7" fixed openings. Is there an easy way to use them?
What are some other options for mechanical filtration with this setup?