# Durso Downflow



## dp0350 (Mar 31, 2007)

I recently bought a reef ready 90 gallon. I understand that the return must be routed through the bulkhead and then back into the tank. However, with the drain I am not sure how to plumb it. From searches on the internet it seems that some people use a Durso plumbing system but there is not much on this forum. Do these systems quiet the drain that much? I am also concerned about making the drain pressurized. I would think that drains should flow to the sump by gravity and not by suction/siphon.


----------



## caferacermike (Oct 3, 2006)

http://www.dursostandpipes.com/

Here is a great website explaining them a bit more. I've only met one person running a drilled tank not running one. He had an early Oceanic he got used. Alex worked with me and was really proud he scored a 220 Oceanic brick with dual overflows, tank, stand, sump, skimmer for $500. He asked me why it was so loud. Confused I went to his place to check it out. The owner used the cheap set up that came with the tank. It was nothing more than a piece of PVC with hundreds of holes drilled in it and foam that went around the pipe. It was nothing more than an open drain. The water going over the overflow fell about 16" to the couple of inches of water in the bottom. It was very loud with both overflows. From time to time one would back up and then force itself to catch up, sounded like a toilet flushing. We went to HDepot, about a 5 minute drive. For $20 and within an hour, we had both overflows rebuilt and running silent.

I've made one more improvement over the standard Durso I like to share. When I drill the hole in the top of the cap for air, I like to over size it and tap it with a 3/8"NPT tap. Then I add a 3/8" John Guest MTxslip 90. To this I push on a piece of 3/8" tubing long enough to drop back to y sump. I add a push on JG ball valve Reaching under I can adjust the ball valve for the perfect rate of flow through my Durso without any noise. By allowing the air to be drawn in from under my cabinet I also remove the tiny amount of noise added from the air being drawn into the system. It gets muffled by the cabinet.


----------



## jtma508 (Jan 1, 2008)

It seems like the prevailing thinking is that these are superior to HOT overflow boxes for supplying the sump. I was leaning in the direction of using a durso with a corner champer when I set-up my 90gal. That was until I learned that the bottom of my tank can't be drilled (tempered).

But then I thought, why can't I come in from the back? Does anyone see a reason why this wouldn't work?


----------



## SKAustin (Aug 1, 2006)

jtma508 said:


> But then I thought, why can't I come in from the back? Does anyone see a reason why this wouldn't work?


No reason why you cant have the back of the tank drilled (unless the back is tempered). With the back drilled, you can opt to install a coast to coast overflow. They are much more asthetically pleasing, and less intrusive to the rockwork.


----------

