Advice needed on overflow box size

[Tom Toro]

I had the last straw happen with my oveflow box. The acrylic actually split apart and it fell down with the siphon still holding. Luckily it continued to pour into the broken part and continued to go into the sump so no flood.

I have a 240gal 8'x2'x2' tank. It's got 2 x 1200gph overflow boxes plus one 600gph box going to the sump. I have a Mag 24 and a Mag 7 pumping it back. I'm constantly re-starting the tubes for siphon. If I don't keep up with it, it overflows the dt.

Q:Would it be overkill to buy the glass-holes largest size overflow x 2 (2" bulkheads)? Or will the 1500gph 1.5" kit be enough for that size tank?

I would be buying two of each kit for either side of the tank.

Thanks,
Tom

[jimsflies]

I think you could cut down on the flow through your sump. I've yet to see a lot of good info on sump through put, but I think 10-15x per hour woud be plenty. Really I think the controlling factor is whether or not you can maintain the set temperature in the display tank assuming your heater/chiller is in your sump. Of course filtration plays a role as well. But slower is probably better with skimmer performance and nutrient uptake with refugiums, ect. The only other negative to low flow rates is that detritus will accumluate more in the sump. (But it probably will anyways...I have a lot of flow in mine and I wet dry vac it out every six months.)

You could ease up on the return flow and increase flow using powerheads if you feel you need more (which you would).

You are currently using an external overflow box? I've never used an overflow that required a siphon. It always concerned me that it would stop after a power outage and not restart (causing a flood).

[Tom Toro]

Thanks for the input, Jim. I ended up buying two of the their largest overflows. Then if I need to go bigger with my pump or completely change out my sump system, I'll be ready for anything. I figure I'll still have the same flow through, just won't have to worry as much about flooding the DT.

By the way, Glass-holes was great about this. I got a deal and some great info.

[jojo22]

Another thing to consider when re-plumbing, why not do a loop return?? All that flow you have would be better spent with one (IMO).

[Tom Toro]

Another thing to consider when re-plumbing, why not do a loop return?? All that flow you have would be better spent with one (IMO).

Do you mean drill some more holes and set up 4 nozzles for the return? If acrylic is really as easy as everybody says it is, then maybe. What were you thinking?