At my wit's end - water level issues - please help!

[Punchanello]

Hi All,

This has got me stumped...I have an internal overflow with a herbie style set up that has a gate valve to control the water going down to the sump. It's an all in one Cade Pro-Reef which is very similar in set-up to Red Sea. I am running a DC Sunpole Magnus 9000 lt/h return pump (not my first choice but that's another story). I think this is sold as an aquamaxx on the US market.

I can keep a steady water level for up to 24hrs-48hrs then suddenly it will increase the level in the main tank, draining the sump and dumping all my gravity fed RO water in to the sump. This has been going on for months.

I have always found it difficult to keep a consistent level which seems to require millimetre by millimetre adjustments. But this is just a new level of irritation.

I have tried and checked -

- the return and drain piping and valves. No snails or blockages. All cleaned thoroughly anyway.
- return pump cleaned twice. No real build up and all clean.
- removed my entire manifold altogether and replaced pvc return plumbing with soft tubing to remove hard corners.

I'm not sure what else could be wrong. Does anyone have any suggestions? Could it be a pump malfunction?


I've added some photos to show the setup

 

[Rjukan]

Describe the route your drain line takes...

Is it the black pipe in the first and 2nd pic that reduces to a smaller flex hose then a 90* elbow to a portion that runs horizontally? If so how far is the horizontal section before it exits into the sump?

 

[DLHDesign]

Hard to tell from the pics, but it looks like your drain lip is pretty close to your water line?
If that is the case, you may be getting some air drawn down, which can impact the consistency of the drain line. Ideally, the primary drain lip should be about 6" or so below the water line (or lower depending upon the flow rate, etc.). It shouldn't be drawing air unless it's turned off, in other words.
Your emergency drain lip should be above the water line during normal operation. Having more distance between the lip of the primary drain and the lip of the emergency drain will help keep things in the right state easier (especially as the pump drops in flow rate as it gets dirty).

 

[RamsReef]

You say you have a gate valve, it doesn't look like you do from pictures.

Could be your pump, you should only need to tweek about ever 2 months, at least that's about my tweek rate, and that's because I don't clean my pumps.

 

[NaH20nerd]

You’ve narrowed it down to the only two things it could be. Water flow through the system or the pump. Without seeing (or hearing) what is happening when you have this event it’s difficult to say with any certainty. I’d also be curious to see how you’ve plumbed the AIO to the sump, typically those are meant to be ran without a sump, so I’m assuming it has been modified. If you’re running the sump dry, and not overflowing the DT, the water is going somewhere else.

 

[Brad Miller]

Gpm to display needs to match the gpm to the sump at all times.
Looks like you’re reducing the drain to the sump manifold and over time this would cause a higher level in the display tank

 

[Brad Miller]

The gate valve is to adjust what flows to the socks versus what flows after the sock to balance flow to sump, but the smaller line size needs to be increased before that can happen

 

[DLHDesign]

To clarify, my assumption is that;
Pics 1 and 2 show the return line ONLY; no drain lines.
Pics 3, 5, and 6 show the drain lines. They appear to be mostly straight 1" hard plumbing. The gate valve in pic #3 is on the primary drain line - which has the gray cap in pic #4 and 5. The emergency drain is the black-topped line from pics 4/5 (and seems to be located underneath the weir extension, which makes it hard to tell what it's opening is like).

 

[Punchanello]

Describe the route your drain line takes...

Is it the black pipe in the first and 2nd pic that reduces to a smaller flex hose then a 90* elbow to a portion that runs horizontally? If so how far is the horizontal section before it exits into the sump?

The drain line is from the overflow straight down to the grey PVC pipe running in to the filter socks area.

The horizontal hose you see is the ATO outlet running to a float valve. That's just the stock set up on the system.

 

[Punchanello]

Gpm to display needs to match the gpm to the sump at all times.
Looks like you’re reducing the drain to the sump manifold and over time this would cause a higher level in the display tank

The manifold has been removed altogether. You can see it the white PVC and ball ball valve in the pictures but it's been disconnected.

The drain runs straight down to the filter sock area with a ball valve in between.

 

[RCS82]

You have 1 drain line and 1 return line?
Its 1 internal overflow with 2 bulkheads?

 

[laverda]

I would lower the height of your main drain. I would also put a screen on it so nothing can get in and restrict the flow.

 

[Punchanello]

To clarify, my assumption is that;
Pics 1 and 2 show the return line ONLY; no drain lines.

Correct. Just wanted to show that there were no kinks or anything and no manifold connected. It runs straight up to the DT from there. The other pipe you see in that pic is the gravity fed ATO pipe.

Pics 3, 5, and 6 show the drain lines. They appear to be mostly straight 1" hard plumbing. The gate valve in pic #3 is on the primary drain line - which has the gray cap in pic #4 and 5. The emergency drain is the black-topped line from pics 4/5 (and seems to be located underneath the weir extension, which makes it hard to tell what it's opening is like).

Yes that's right. The emergency line is not easily accessible from the lid that gives access to the weir/drain section. It sits an inch and a bit above the level of the primary drain.

Just to be clear I use a little mark inside the weir to try to get a consistent level. It takes some time to adjust but the water level will sit at that mark for 24-48 hrs consistently, then suddenly rise without me even going close to the tank for that period.

I keep the water level higher in the weir/return area than the minimum level of the weir which is an inch or so higher that the primary drain and about half an inch lower than the emergency drain.

 

[Punchanello]

You have 1 drain line and 1 return line?
Its 1 internal overflow with 2 bulkheads?

1 primary primary drain, 1 emergency, 1 return. It's an internal overflow but sits in its's own compartment which is as tall as the tank. Two bulkheads which exit at the bottom and f that compartment.

 

[Punchanello]

You’ve narrowed it down to the only two things it could be. Water flow through the system or the pump. Without seeing (or hearing) what is happening when you have this event it’s difficult to say with any certainty. I’d also be curious to see how you’ve plumbed the AIO to the sump, typically those are meant to be ran without a sump, so I’m assuming it has been modified. If you’re running the sump dry, and not overflowing the DT, the water is going somewhere else.

The ATO is stock with the tank. The tank has a rear compartment which houses the ATO water and overflow section. The ATO is gravity fed down to a float valve. The feed pipe is the horizontal thing you see in the first picture. It's clunky but literally won't feed water unless the return chamber level in the sump drops.

 

[RCS82]

Only a trickle of water should be going thru your emergency drain. It can be the same size plumbing as the main drain. Just needs to handle a little excess water sometimes, should be real simple.
I run a 2 drain Herbie in an internal overflow, main drain in front below the water line and the emergency is behind it just above the water line. Never a problem and always silent.

 

[Punchanello]

Only a trickle of water should be going thru your emergency drain. It can be the same size plumbing as the main drain. Just needs to handle a little excess water sometimes, should be real simple.
I run a 2 drain Herbie in an internal overflow, main drain in front below the water line and the emergency is behind it just above the water line. Never a problem and always silent.

Ok, so you allow a trickle down the emergency drain all the time?

 

[RCS82]

Yes, put 90% or most of the water down the main with the valve. That valve you close til the water is just above the main drain which makes it silent and sends just a trickle of water down the emergency, which hopefully and in most cases is silent too. That way if something changes with your return or the main gets clogged a little, the emergency has extra room to deal with the water.

 

[Punchanello]

Ok, so I've checked and I'm told by my local distributor that water is supposed to flow over the weir and down in to the overflow section (lower water level than the DT) and only be high enough to avoid gurgling at the mouth of the primary drain. I ran it this way for 12 hours and the level was millimetre consistent the whole time then suddenly the water level dropped in the sump and rose in the DT again.

I've pulled apart, checked and cleaned the drain and gate valve again. Nothing.

New experiment - I'm running the return pump at full speed. There is no blockage in the drain. If it keeps a consistent level at full speed then that goes some way to telling me it is a problem with the pump and not a blockage. Theoretically if it's already at full speed it can't suddenly increase flow. If I still have the same problem then I can only think of two things, and I'm reaching here -

1. A faulty gate valve. I'm not sure how this is possible because it looks clean, good quality and I can see no problem with it on inspection but there you go.

2. This is a really long shot but maybe my return plumbing? It's clean and obstruction free but it is vinyl tubing. Could the suction or pressure of the water flow be causing it to contract and expand altering the water flow? I don't know. Seems far fetched.

Any further thoughts?

 

[Punchanello]

Hi Everyone,

I have done a couple of additional experiments -

I still had a suspicion that my return pump was the culprit. I ran it at 100% on the theory that a return pump can't do 110%, so if the water level rose again, I could rule it out as the problem. 24hrs later, the tank level rose again. Not absolutely conclusive but still pretty sure it isn't the return pump now.

I am now trying to run without any mechanical filtration. Socks, filter wool etc. So far, no water level changes in 28 hrs. Here is what my filter sock compartment looks like -

I change my filter socks regularly, like every 3 days. I don't really understand the hydro dynamics at work here but is it really possible that any slow down from slight build up in the socks would result in a build up of water in the DT with the setup I have? Wouldn't it just start overflowing at the socks rather than rising levels up-stream in the tank?