33 Cube - the work begins

[kimoyo]

I think its just that he drilled his hole too big for the flow he's pushing thru it. It would be nice if the cap was shorter than tank lip because if the water ever backed up for some reason it would cover the hole and siphon the water level down.

 

[masterswimmer]

Dmitry,
I agree, the water level in the overflow box needs to come down to the 'T'. Not above it.

Also, the closed loop pump will have a 1" inlet and the discharge is 3/4". That can handle a good amount of flow.

Pumps:
PanWorld 100PX-MD40R
PanWorld 50PXX-MD30X

 

[Dmitry]

All the photos of the dursos I've seen also have the water level much lower, but that's how it came to me. I can make another cap, but the smallest drill bit I have is that same size! And it looks pretty small already, to be honest. Smaller would have to be a needle!

The overflow is 1'', the return is 3/4''. And I put on a Mag 5 on the return. Am I still returning more water than draining into the sump? And if the hole in the cap is smaller - the level in the overflow will go down?

I just aquscaped the tank and filled it with salt water. Here are some final results. The pictures suck though.

 

[Dmitry]

Oh, and I seem to have forgotten how to set up my Ranco double temp controller. If I want the temperature to stay at 79-80 - what's the best way to set it up? And what should the differential be? I set it to 1, but the directions say 2 is optimal.

 

[kimoyo]

Its either too much air or too much water in the pipe. So you could either slow down the water flow going down (by cutting back your return) or slow down the air flow going down by making the hole smaller.

I'm not sure how bad its going to be with the water level running there because I don't have experience with dursos. If its quiet thats good. But if for any reason it starts to back up then you could get a flood. Do you have another shorter piece of pvc pipe that you could put under the tee so it lowers it? Don't cut that piece down in case it doesn't work for some reason. I'm asking because if the top of the hole is under the tank trim then when the water goes over it should siphon.

You might want to test flood scenarios by temporarily putting a valve on the drain to act like a clog and slow the flow down to see what happens. While your standing there watching the water rise see if it siphons once the water goes over the hole.

If you haven't yet, take a look at this page from the website Wes posted,
http://www.dursostandpipes.com/BuildYourOwn/tabid/54/Default.aspx

 

[Dmitry]

It says that the water level in the overflow is supposed to be a bit lower than in the main tank. That's not the case in my set-up - they are identical. I'll try a smaller hole. The only way to bring the top of the durso below the overflow level is to cut PVC more. Anybody see a problem with that? It's already pretty low.

 

[Dmitry]

I just did a test using that most useful item in the world: duct tape. I taped half of the hole and the level dropped to the T and then went up again. And it does this every 20-30 seconds - up and down. Making a flushing sound in the process. Is this the normal procedure? I'm not sure I like the flushing sound! The more of the hole I tape shut the more frequently it does this.

 

[masterswimmer]

The hole is not too big. If anything it might be a tad too small. Try taking off the pvc cap leaving the durso with a large open hole. See what happens. It will definitely stop the flushing noise. I want to know if it lowers the level in the overflow to the 'T'.

R

 

[Dmitry]

When I take off the cap the water stays above the T, leveled with the water in the tank. It's noisier than with the cap on.

 

[masterswimmer]

When I take off the cap the water stays above the T, leveled with the water in the tank. It's noisier than with the cap on.

I knew it would be noisier than with the cap on. It was just a test to see where the water level would go with a 'larger hole'.


Do you have the overflow hose submerged in the water within the sump?

 

[Dmitry]

Do you have the overflow hose submerged in the water within the sump?

Yep, it's submerged. In reading that durso website it says it needs to be only about an inch below surface - which it is, but there's a filter sock on it and these suckers are pretty thick. Perhaps the end of the pipe in the sump is up against the filter sock and this causes backpressure.

 

[masterswimmer]

The overflow drain hose should not be submerged at all. It is creating a siphon as opposed to an overflow. You need to have the hose ABOVE the water level in your sump. Doesn't have to be but 1/2" above the water, but it does need to be above the level.

Before cutting your tubing, just raise the hose out of the water and see how the overflow responds.

R

 

[Dmitry]

Just took it out of water (still in the filter sock) and no change in the overflow level. Not sure if the fact that's currently angled is another factor. But the only way to angle it directly down is to put a 90 fitting on it.

 

[masterswimmer]

I should have been a little clearer. I hope you tried it out of the water with the cap OFF the Durso. I'm thinking the problem is two-fold. One, the flex pvc is submerged AND the hole in the Durso is too small.

 

[Dmitry]

No change with the cap off.

 

[masterswimmer]

No change with the cap off.

Damn, I was hopeful with that combination. Dumb question, but I have to ask. You don't have a ball valve or any other restriction on the flex pipe overflow, correct? I know the answer, but have to ask. :Up_to_som

 

[Dmitry]

No, the only ball valves on there are on the closed loop.

I can lower the durso a bit more, that'll probably lower the level of the overflow - but is that the right solution and will it lower the level of the water in the tank? (In the tank the water is already below the rim.)

 

[masterswimmer]

Lowering the water in the overflow shouldn't effect the water level in the tank. That will be governed by the amount of water being returned by your return pump.

As you know, none of the Durso pieces are glued. This should offer you some flexibility in trying some different solutions. I would definitely try various height combinations to find the right level.

 

[Dmitry]

I'll try to cut the PVC a bit more tomorrow to see if lowering the durso makes a difference. Though I'm afraid all that's going to do is lower the level of the water with the durso - not lower it in relation to the durso, and the water will still be well above the T. :banghead: Stay tuned...

By the way, how low can we go? The opening of the T will need some room to take in water, so how many inches from the bottom of the overflow box is the cut-off?

 

[masterswimmer]

Once again, trial and error. I'd think an inch and a half below the elbow should be plenty. But try a few different heights. You mentioned you have some extra 1" rigid pvc. It's easy to try a few fixes to find the most suitable one.