Help me with my HOB overflow!!

It depends.

Some use a Deep Sand Bed (4 inches or so) and Caulerpa. In that case the fuge should be about 1/10 the main tank's size with about 1/10 the main tank's size in flow (75 gallon tank= 7.5 gallon fuge (just use a 10 gallon tank) with 7.5 gph flow).

My brother-in-law has been running a DSB in his fuge without any macroalgae and the same very slow flow. He's used that setup for over ten years.

I've also seen no sand in a fuge. Still same 10 gallon tank, but about 100gph with Chaeto.

I've seen 1 inch of sand with Cheato and a 10 gallon tank with several hundred gallons per hour.

As with almost everything in this hobby, it's really a matter of taste.

I run a 10 gallon sump/fuge (all I can fit under my tank stand; my wife said whatever I do it must fit under the tank as she doesn't want to see it). I wish I could do a separate sump and fuge. :-/ I run about 130-150 gph through mine (even though the pump is rated for 190 at 3.5 feet of head I don't think it's actually that much as the flow is gentle) with 1.5 inches of sand and couple of pieces of live rock. Once my tank is more mature (I restarted it on 6-14-08 ), I will add either Mangroves, Chaeto, or Caulerpa. Not sure yet (still researching as everyone has their own opinion on which one is best). This is not the most optimal setup, but it's the best I can do with my limited space (I can't get anything larger than a 10 gallon tank under my stand).

 

Thanks dude.......