too much flow?

[DeMarcusR]

I just finished re-plumbing my 180 and almost had a small flood in the living room. I'm running a little giant 4mdqx-sc, which should work out just fine. This is the same pump that was on the tank when I got it - Should be less flow since I have the chiller plumbed into it.

Details:

Return pump - LG 4mdqx-sc
Return plumbing - 1in to 3/4in pvc w/ 4x90* elbows, 3x45* elbows to trim off some of the excess flow.

Drains
1in pvc dursos
1in pvc all the way to the sump. NO 90* elbows. just 2x45* elbows

So, what am I doing wrong? Should I drill larger holes in the top of the dursos or what?

Thanks for the help!

 

[DennisF]

Did you know that 2-45 degree bend create more head loss than 1-90 bend? Not that that is the reason for your problem. I would check for blockages in the return piping and the valves to make sure they are opened. Is your durso a store bought or DIY?

 

[gmax]

I dont think this is true. Every 90 drops your flow something like 6 - 7%. 45s are much better in plumbing. But if you want to get the most flow, use spa flex for the returns, no angles at all!

 

[DeMarcusR]

@DennisF wrote:

These are DIY dursos built by a plumber friend who's also in the hobby.

The durso are made from a 1in pipe going into a 1in 'T' with a 90* elbow coming from it.

like the one pictured here

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Did you mean check the drains for blockage?
Everything appears to be flowing fine. The only valvues are in line with the return pump. 1 where the sump connects to the pump and 1 right before the 'T' going to the tank return for the chiller.

 

[bimmerzs]

Marcus,

I thought you needed to have larger diameter PVC for the durso's but not 100% sure. Looks like it goes down to 3/4 inch at the bulkhead, if so that may be your problem.....or at least part of the problem I would check this site out. http://www.dursostandpipes.com/

Cheers,

 

[disbjohn]

yeah..i would have went with 1.25 thinwall pvc down to the very bottom and add a reducer to 1" there.

 

[gmax]

Pull the standpipe and just let it drain noisy for a bit. does the drain keep up with the returns that way? If yes, then the problem is with your standpipe.

 

[DennisF]

Yes it is true that 2-45's have more head loss than 1-90. I do this for a living and have the registration to back it up! But seriously, the durso needs some vent holes in the top and in the tee area for proper venting. If I can get my wife to take some pics I will post my adjustable dursos that I made for $12. :lol:

 

[gmax]

I am not a plumber and dont claim to be. But there is a head loss caculator on RC that everyone uses. If you put in some parameters and hold everything constant but 1 90 or 2 45s, you get virtually the same head loss. Any difference is so small that it would not be perceptible in your aquarium application. Which means that a 45 is much better for flow than a 90. Put another way water does not like to go around corners. Too much friction.

 

[DeMarcusR]

@gmax wrote:

It's definately the standPipe. I removed one of them (the only one I can get off without removing the canopy). When I removed that one and opened the ball valve all the way - that one drain was taking enough water for both drains...


@bimmerzs wrote:

The picture I posted is from the website quoted. Everything on my drains are 1in, there arent any reducers on there. So, should I make the standpipe itself 1 1/2 inches?


@DennisF wrote:

Thanks for the info. I'll definately keep this in mind when / If I replumb.
I figured 2x45* would be less loss... At this point, it appears I need more loss so I can have less flow.

As far as venting, the standpipes have a 1/4in hole in the bottom elbow and about 6-8 1/4 in holes in the lid.. I started poking holes trying to get the drain to be more efficient..

Funny you should mention adjustable dursos.. I was going to buy some of the adjustable pipe repair pvc when I was at the depot but forgot so I just used the 1in that I had here. I'd love to see pictures of yours, if you get a chance to post.

 

[DennisF]

Here is a pic of the durso I made using a pvc pipe repair closure from Home Depot.

 

[bimmerzs]

@djr2001 wrote:

Here's the quote from the website under the build your own section. :wink:

@The Durso website wrote:

Cheers,

 

[DennisF]

The nice thing about this design is you can adjust the water level in the overflow area and the flow by raising and lowering the head. Notice the holes in the neck portion of the tee. This help in the flow rate of the pipe system and helps keep it quiet. This is a copy of the Magnaflo stand pipe using pev fittings availabe at Home Depot. If your overflow box is large enough for theflow yu want, if you make this one you should be able to get the flow rate you are looking for.

 

[DeMarcusR]

Hmmmm. 9:53... wonder if I can make it to homedepot by 10 :lol: prolly not... I'll head over there tomorrow and pick up some 1 1/4 in pvc and some reducers. Guess for the time being, I'llhave to deal with the growling and slurping...

I'll give that a try and report back to you professors tomorrow 8)

 

[DeMarcusR]

I guess I mis-understood what was being said about the 2 - 45s and headloss. I didn't realize I should account for headloss on the drains....

anywho - I made new dursos this afternoon with 1 1/4in pvc.. Replumbed a few things while I was tearing things up - fire the pump back up, even opened the valve for the chiller.. Tank STILL overflowing... Guess I'll head back to the depot tomorrow to get some more 1in 90s.. Thought I had enough but ended up redoing quite a few things..

If this doesn't work... I'll probably end up paying someone to replumb the whole thing...

 

[rckrzy1]

@DennisF wrote:

But most places I use 2 45's instead of 2 90's . Unless your saying a ONE 45 has more loss than ONE 90 ?

And for 1 1/4 you will not find thin wall at any HD I've been to. But the thick wall 1 1/4 is still a larger inside dia than a 1" thin.

 

[DennisF]

I am a little confused on your situation. You have a 180G tank right? You need approx. 4 times that in gph which is approx. 720 gph. Your two dursos should easily handle that amount of flow. How much are you pumping into the tank? Do you have a recirc. valve on the pump that drops back into the sump and a valve on the pump discharge line for flow control? A one inch discharge should handle about 600 gph maybe a little less with the durso system on it, but that is still quite a bit of flow. OK, I just looked at the pump rating for your pump and it is very likely that the pump can over run your overflows with the drain pipe size you have. Try valving it down. Your pump is rated at about 1000gph at 6 feet of head, which is around where you are.

 

[DeMarcusR]

@DennisF wrote:

I'd guestimate the pump is pushing about 800gph to the tank after the few bends and being split to the chiller. Do you think the 2 45 back to back is creating the problem? I'm probably just going to replumb everything. I just bought some 1 1/4in pipe to run all the way down to the sump. I'm going to replace the 2 45* on the one side with a single 1 1/4in 90*...

To answer your question about the recirc - No I dont have one. I actually thought about doing that also - as well as just plumbing the ca reactor and 2 phosban reactors into the line....

Hope I cleared up the confusion - if not, I can try to post pictures..

Thanks very much for your help!

 

[melev]

A 1" bulkhead can drain 600gph. You have two. That means your tank should drain 1200gph. Yet your tank is overflowing. Which means to me that your tank is receiving more than 1200gph from that pump.

On your Dursos, you mentioned you drilled a bunch of holes. Take some duct tape and cover them all, sealing the top. That will create suction, and you can check to see if the tank will keep up with the pump. If it does, poke open one hole on each, and see if the tank still keeps up.

The drains in your sump should only be submerged 1" under water, at the most. 1/2" would be better. Just enough to keep it quiet without splashing. If it is submerged more, the plumbing is fighting back pressure.

 

[ss95003]

@gmax wrote:

If there is almost no change how is the 45 much better for flow? Wouldn't they be about the same since that is what the numbers say?