Having plumbing issues with recently launched tank

[AndyR83]

Hi everyone,

I’m hoping to get some insight regarding water flow and/or plumbing issues I’ve been having. I recently upgraded from a 55g tank with HOB overflow to a drilled 220g. This was my first time plumbing a drained tank and I anticipated some bugs that would need to be worked out, but overall things are generally working pretty well so far. I have two issues that I’m hoping the group may be able to help me work through:

First, I’m constantly finding that my return pump is outpacing my tank drains. The water level in my sump’s return compartment is inconsistent and generally low enough that the pump sucks air unless I throttle it way down. I’m constantly adjusting the ball valves on my return lines trying to maximize flow. I can only raise my return pump to the 2nd or sometimes 3rd power level (out of 6.) I don’t feel like the turnover I’m getting in the DT is adequate. Is there anything I can do to fix this? Note that I don’t currently have an ATO but this is something I’d like to add at some point.

The second issue I have is that whenever I turn off the return pump, after a few minutes, the sump water level slowly rises until it overflows. This means I have to close all the ball valves whenever the pump is off, which is a huge pain. It also makes me worry about losing power or something when I’m not home. Is there anything I can do about this?

Tank
72” length
24” depth
30” height
12mm glass thickness
220g display tank volume
4 bulkheads total (2 per side)

Sump
Eshopps ADV 200
30” length
14” depth
16” height
30g approximate sump volume

Pump
Hydor Seltz D 3200
3200gph
Currently submersed in sump

Plumbing
All 1” PVC
2x Durso style drains
2x 3/4” Loc Line returns w/ flare nozzles
(These were each dual returns when I got them, but I changed them both to singles by removing the Y splits)

Thanks for any thoughts you may have! Much appreciated!

 

[Dragon174]

There are a couple of things that you can do about the sump overflowing when you turn off the pump. Raise your return lines closer to the water surface so that it breaks siphon when the pump turns off. If you can't raise them up enough (would need to see pictures of where your returns are) you can add a back flow check valve on your return line just after your pump. I did this for years. My new set up doesn't have enough room for one and really miss having it. You can get them at any hardware store in the plumbing isle. You may have to step down the fittings as most of them come in 1 1/2" slip fittings, but its not hard to do.

 

[homer1475]

Are your return lines submerged in the tank? I would guess that your getting a siphon back into the sump from the return nozzles. Just lift them up a bit, or drill a small hole in the underside.

Pics of the whole setup whole help diagnosing the problems.

 

[Shorething]

I have the same tank. I run a cor 20 pump and I believe it's about 2000 gph. I have plenty of flow through my trigger triton sump. With two mp40 powerheads.

 

[Shorething]

I also tested for power outages and adjusted my returns and drains for sump overflow.

 

[Snoopy 67]

Durso's can NOT handle large flow well.
I run a 250 with dual overflows using a Herbie Drain & have plenty of room for flow using 1" piping for drains.
You will have to return over the back of the tank with this system.
Generally sumps run around 1/2 full because of back flow on a shut down

 

[mfinn]

Sounds like the return outlet in the tank is too low.
The amount of flow back through the sump can be as low as 3x the tank volume, but 5x the tank volume is more than adequate.

 

[ca1ore]

The fundamental problem is that two 1" durso drains are nowhere close to being able to handle 3,200 gph (even adjusted for head pressure reductions). A single 1" durso is best limited to 500 gph, so that is why your drains cannot 'keep up'. The amount of head build up over theses drains is likely why your sump overflows when power is cut. You may also have return back siphon.

Frankly, the dual corner overflow tanks don't work well. You'd be well served by converting both to herbie drains and going over the rim for the return.

 

[nereefpat]

Yep. Step 1, fix the siphon issue so the sump doesn't overflow when the pump shuts off.
Step 2, valve the pump way down, or convert both drains to Herbie systems

 

[AndyR83]

Thank you all for your thoughts so far! As requested, here are some pictures. My apologies if the night lighting made any of these challenging to see. I can try to retake in better light if needed.

Left overflow:

Bottom of left overflow:

Left half of plumbing:

Middle of plumbing:

Right half of plumbing:

Right side overflow:

Also, here's the position of my returns. They're almost exactly at the surface of the DT water.

 

[Albertan22]

Your sump seems quite small for a tank that size and the flow you are going for. You’re always going to drain somewhere between a half inch and an inch of water when you power down your pump as that’s what drains down the overflow before it stops. Then you have back siphon of the returns until the siphon breaks, plus the water volume your drains and return lines hold. All in, for a tank that size you’re going to back drain at least 8 gallons no matter the scenario, possibly 10-12 gallons. If you’re starting with a 30 gallon sump that’s 1/3 of your volume that you need to keep empty for backflow! My old 120G tank had a 40 gallon sump and my new 180G tank uses a 75 gallon sump. Both were designed to operate quietly and allow backflow during shutdown.

Running the flow you’re talking about through a sump that small will be incredibly noisy too. Since you already have the setup you’re probably best to slow your flow and add powerheads to the DT.