[SmallFry]

Originally Posted by ensquire

Thanks and now the next series of questions. LOL
Drain is a 1" bulkhead with a 3/4" straight pipe and the drain has 3/4" pipe with 2 elbows draining into sump. Return is a 320 GPH pump hooked to a short piece of hose into a 1/2" run about 3' long with 2 elbows attached to a 1/2" bulkhead with a 1/2" pipe into a Locline nozzle. I don't like the open drain, and have experimented with several types of drains, but whenever I change from the straight open end I have to throttle back my pump. I would like and need more than 320 GPH flow, which brings me to
My questions about my options.
Is there any effect on the drainage if I make the pipes bigger before and after the bulkhead? It is still a 1" opening.
I see several options but would like to get some opinions and feedback on them.
My first thought was to order some glass bits and bore out the openings inside the overflow box but my concerns are about how close the boles will be and the space underneath would be tight but might be an option.
Option 2) Use both lines in overflow box az drains (Herbie, or other).Increase pipe to 1 1 1/2 before bulkhead and 1" after. Run an exterior line up the back thAt would tee off into 2 returns drilled thru back of the tank and use nozzles to have some flow behind the reef. in the tank. If this is best option, should the return be a single line or double and should it be 1/2, 3/4, or 1" based on the size of the drain?
Option 2) use 1' bulkhead in overflow box as 1' return line and use second pipe as emergency overflow. Then build either an interior or an exterior overflow box on the back of the tank?

I would like to increase my pump to a Quiet One pushing 800 GPH if I can work out this plumbing problem, and I am really stuck here. My tank has been running for a month now with only the liverock in it and I am dying to start stocking it, but I feel that this will be a mistake until I address this plumbing/flow situation.

Thanks.

Mike


Or option 3) I am overreacting and I should be happy with present situation?

I've recently finished plumbing my 75 gallon, and some of my experience form doing this might be applicable given some of your bulkhead sizing and the newer pump you're talking about. I'll be honest though and say I'm no expert as this is my first system with a sump..

My system is running a quiet one 4000, that given the head height I reckon is probably (according to the graph on the box) pushing 600 - 800 gph. I'm running on 1" bulkheads with 1" drains also. The drain system I chose is a three drain herbie (also sometimes referred to as a bean animal), I realize that you only have two holes, but the third drain is just an extra paranoia measure which I could easily accommodate by just adding an extra hole in my overflow box, so I did it while I had the drill out.. The returns are 1" single up to about the level of the bottom of the tank where it splits and goes up the back of the tank and over the edge, also in 1". I then have some 1" pvc end caps that I've drilled 5/8" holes in to get a bit of pressure behind it (these aren't glued so I cab remove/redrill/replace as whim dictates..

There are some pictures of my set up in the build threads on my sig. They probably explain it far better than I have! The early for the 75 are in the latter parts of the 27 log - and why not, because that makes complete sense!

I found that with the return pump at full belt I still have to close my ball valve somewhat in order to make any flow through the second drain and keep the main one air free, so one 1" with 1" plumbing downstream drain can handle in excess of the required flow from my pump. You mentioned that there were two holes in the overflow box, if one is 1" then you're home free, because your main 1" drain can handle the flow plus some, then your second can also handle it if the main one blocks completely, and a herbie is totally doable.. if the second hole is the 1/2" return you mentioned, then things become more complicated, or you may have to accept that you can't handle the flow if your main drain blocks completely (how likely a complete blockage is I don't know) surely though, it's safer than a single drain..

If you build an overflow box I'd vote for external - I really like mine a lot because it doesn't intrude on the tank at all. I'm so glad I didn't go internal as I'd originally planned. Now if I can only stop the cats trying to drink out of it..

Either way, I'd be very tempted to get rid of that 3/4" section in your drain, no doubt that would increase your drain flow a lot, and save you throttling back the pump...