HOB Filter

[Wild1]

Recently, I have seen a couple of videos with HOB filters on the refugium along with the regular tank filtration. Has anyone done this, and is it a waste of time? TIA

 

[Ron Reefman]

I've never seen it done, but no reason I can think of to say it could be useful if you need the extra filtration. But to me it seems to be about equal to using a filter sock. But then I never put carbon or anything but filter material in the HOB filters I use on my 2 smaller tanks.