Question about bulkheads

EFSleeper · Aug 20, 2013

Ok so I'm about to tap my first tank really soon. I'm trying to get everything ready for the process and got a few questions on the bulkhead sizes. A little about the tank it is a 6 foot 125 running a 55 sump and once it's running will also be running a 55 frag tank and a 75 display fuge. So I have been doing some research on it and my first question is would it benefit more to have 2 1200gph over flows or just 1 center tap 2400gph? Next question is every where I have checked says 125 should have 1 1inch bulkhead to drain and 1 3/4 for return. Does that sound about right or should I go bigger? Sorry for the questions just this will be the first drilled tank I've owned and just wanting to make sure things are right from the start so i don't have to redo anything.

AZDesertRat · Aug 20, 2013

I doubt you will want or need 2400 GPH overflow capacity. Many will recommend a 3 to 5x the display volume turnover which is only 625 GPH. A 1" overflow will handle that plus a little more, I am pusing around 850-900 GPH through a single 1" overflow and standpipe myself on a 100G mixed reef. I push the 5x display volume a little but 2400 would be way overkill.

I would design the overflow for a maximum of 1000 GPH so either two 1" overflows or a single 1.5" should be more than sufficient. Many like dual overflows and it does give you a little safety factor if one plugs but myself I hated giving up the real estate two overflows take up so stuck with the single and have never had any problems in almost 10 years with the present tank and overflow.

I also have a sticky post here on R2R with Bulkhead Installation Tips that may be of some use to you.

ReeferBob · Aug 21, 2013

Ha! WAY too much flow. Your sump would be boiling with the water discharge from 2400gph. My 125 uses the two internal overflows with 1" pipes and an eheim 1262 return pump (1000gph). I have the pump cranked down to around 75% or less and that is almost too much.