Durso standpipe help

dinger28

Member
Hey all. My 300 gallon tank is finally up and running and I want to fit the drain with a Durso. The drain is for a 1.5 inch bulkhead. Could I use that size pipe or do I need to go to a 2 inch pipe? A lot of people were saying to go up a size in pipe, but since mine was already 1.5 inches, I wasn't sure. Thanks for the help!

Matt
 
Because you are supposed to use 1.25" pipe with a 1" bulkhead, I think it is reasonable to use 2" for yours.

hth
 
I was figuring that, but wasn't sure since 1.5 inch pipe is pretty big for my drain. Any other suggestions are always helpful from anyone! :)
 
Let me get this straight: You have a 300 gallon tank, and want to run a DURSO type drain on it? The size is practically irrelevant, as the stable flow through a 1.5" durso will be around 350gph, and through a 1.25" ~ 200gph. Going up in pipe size from 1.5" as you can see, is not going to give much improvement. So looking at this from a "Durso" stand point, the 1.5" bulkhead is totally inadequate. In addition, I would well imagine the overflow is inadequate for this size tank as well.

What you do want to do, is start reading here, and head in a completely different direction. Pay attention to the side bar as well. Then go to work. Big tanks are not hobby toys, and it is going to take some work.

http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx
 
You could do a Herbie instead if you want to use the holes you have already. People here love the Bean Animal but the Herbie is sufficient.

I think people push way more flow through their sumps than is really needed in most cases, and you may be just fine with a standard Durso. I wish I would have gone directly to the Herbie on my 120 & skipped the Durso, however.

http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/
 
New Durso

New Durso

I've had just a plain 1" pipe that was open on one end and had about 50- 1/4" holes drilled in it. The total length of the pipe is about a foot long. From what I learned here on RC, I made a 1" Durso standpipe and replaced the old pipe this morning. My overflow in my 180 is about 6"x6" in one rear corner of the tank.

I'd really like to have a backup, but I'd have to tear down the tank to get behind it. Anyhoo, the flow through the new Durso, into both my fuge and sump, then returned to the tank via my 1110 gph pump is perfect!

I'm willing to bet a 1 1/2" or two 1" Durso's would work like a champ for you. Really depends if you can get behind and under your tank with it up and running.
 
I've had just a plain 1" pipe that was open on one end and had about 50- 1/4" holes drilled in it. The total length of the pipe is about a foot long. From what I learned here on RC, I made a 1" Durso standpipe and replaced the old pipe this morning. My overflow in my 180 is about 6"x6" in one rear corner of the tank.

I'd really like to have a backup, but I'd have to tear down the tank to get behind it. Anyhoo, the flow through the new Durso, into both my fuge and sump, then returned to the tank via my 1110 gph pump is perfect!

I'm willing to bet a 1 1/2" or two 1" Durso's would work like a champ for you. Really depends if you can get behind and under your tank with it up and running.

Well it is rather unfortunate that the 1" durso is not flowing anywhere close to 1110gph. If it were it would be unbearably unstable, full of bubbles, and noisy, or there is so little air in it, it is teetering near siphon, and is a flood waiting to happen, and it will not be silent, or stable. The operation of a durso is not luck, it is governed by physics, and you can't beat the physics.

The laminar (safe, stable, quiet, bubble free) flow capacity of a 1" durso is down in the vicinity of 50gph. It follows, given the laminar flow capacity of a 1.5" durso, that durso standpipes are not at all adequate for a 300 gallon tank that should be run in the vicinity of 3000gph.

If it were at all possible to get dursos to perform as some claim, there would be no move to the use of siphon systems to target flow rates above ~350gph, 750gph for dual setups.
 
Ok, Uncle. I get what you're saying, but I don't get what to do about it. Other than the water level being about 6" higher in my overflow, and being much more quiet, it's behaved in a pretty stable way since I did a w/c and installed it this morning.

I really don't want a flood and my wife will beat me senseless if I flood the living room. Are you saying that the open pipe that I took out is better and/or more stable? Thx.
 
An open pipe will behave in much the same way as a Durso, and vice versa. Both are variations of the "open channel" theme. The difference is an open pipe is capable of hitting a "siphon mode" (used here to mean no air in the line, not the true definition of "siphon,") whereas the Durso cannot, and of course one should not run a siphon without an emergency backup.

Larger pipe would help, however, you still won't get the performance out of it. You should be running a siphon system with a 180 gallon tank, hitting 1800gph+, and with a larger overflow. How they come from the manufacturer is a way to do things, but by far not a "great" way to do things. Siphon systems are not hard to get into a corner overflow, (most have two holes minimum,) on the other hand corner overflows are horribly inefficient (size and almost always use "teeth".) After the fact is always going to be complicated, and if it is an acrylic tank, even more so.
 
Hmmmm. Unfortunately, its a Truvu acrylic. It seems to be staying fairly stable, so im not quite as nervous as I was. Would you recommend leaving it or going back to the old straight pipe for safety?

I ran the tank for about 5 yrs, then it's sat in my garage for 10 years, till about 3 months ago. I havent had any issues with the old straight pipe, but I'll go back to it in a flash if there's a good probability that this new one might flood.

The overflow does have the teeth as you mention. I've measured the box a handful of times and I think I'm stuck with a single bulhead in there. :(
 
If the drain is flowing near what you claim it is, it is a flood risk straight pipe or durso. If the pipe gets partially clogged or completely clogged, it is all over. But I think this should be in a thread of its own, as it is kinda hijacking the OPs thread at this point.
 
If you hole is only 1.5" that is all the flow you will flow through the hole. I had durso's on my 120 and hated them. Could not ever get bubbles under control.i eventually went to herbie.
 
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