Overflow and return section of sump empty

[Oberst Hajj]

Sometime over night something happened in my system that caused the return section of my sump to go low enough for the pump not to push enough water back up into the tank.
(no water was going over the baffle from the sump to the return section). When I noticed this I turned the pump and skimmer off and a small amount of water drained back into the return section. I'm assuming that is from the return pipes going back up to the tank.

I also noticed that the overflow area is completely empty (normally just drains down to the two drain pipe levels (a Herbie system). The bottom of my stand had about 2 gallons of water in it and there is some water in the crawlspace below my tank. The floor around and under my tank is completely dry however. There was some evidence of water on top of the doors to my stand, but only a couple of drops.

Any thoughts on what could cause my overflow area and return section to empty, but nothing else in my system?

This is not how my tank looks now, this is from the initial setup 8 months ago. Just trying to give some reference to what my system looks like.

 

[Daltrey]

I would fill it back up, turn it on and see where the leak is coming from. Maybe have some towels handy, ha.

 

[Oberst Hajj]

I just tried adding some water to the overflow area and it started leaking up around the bottom of the tanks frame.

 

[Daltrey]

Is the leak coming from the bulkheads coming out of the overflow? You can just tighten the nut on those. Be careful not to overtighten or you could crack the glass.

 

[sbash]

So, there is a small hole inside the overflow compartment. This compartment is completely sealed from the rest of the tank, hence the display portion being full still.

The loss of water from the overflow caused the sump's water level to drop until there was no longer enough water for the pump to pump.

So, all in all, sounds like you either need to repair your DT or replace it.

The repair could be as simple as putting a giant bead of caulk in the back corner (i.e. where the leak should be). It does not need to be pretty, because it is hidden and probably extremely awkward to get at. BUT look for cracks in the glass, if the glass is cracked you are best to replace the tank (or that entire panel I suppose).

Also. check the tank for levelness (did I just make that word up?). If the tank is not properly levelled, then the caulking could continue to split from the panes of glass. Do this check while the tank is full, with the extra weight on the floor, it could have settled a bit (i.e. it was level when empty, but now that it has been sitting full for a while it could have shifted a mm or so)...

 

[Oberst Hajj]

It is not leaking from the bulkheads. The bulkheads are up high as you can see in this photo (the overflow section is the reflective area in the middle of the tank):

You can see the water leaking out of the bottom frame on the right hand side.

It is coming over the frame in a couple of places. What is interesting is that with the display part of the tank empty, the overflow area does not leak. It only leaks when there is some water in the display area as well. I can only assume that the pressure for the display water cause a small leak to open up in the overflow area.

Now, can this be repaired if it is "just" the bottom seam, or do I need to get a whole new tank?

 

[Oberst Hajj]

So, there is a small hole inside the overflow compartment. This compartment is completely sealed from the rest of the tank, hence the display portion being full still.

The loss of water from the overflow caused the sump's water level to drop until there was no longer enough water for the pump to pump.

So, all in all, sounds like you either need to repair your DT or replace it.

The repair could be as simple as putting a giant bead of caulk in the back corner (i.e. where the leak should be). It does not need to be pretty, because it is hidden and probably extremely awkward to get at. BUT look for cracks in the glass, if the glass is cracked you are best to replace the tank (or that entire panel I suppose).

Also. check the tank for levelness (did I just make that word up?). If the tank is not properly levelled, then the caulking could continue to split from the panes of glass. Do this check while the tank is full, with the extra weight on the floor, it could have settled a bit (i.e. it was level when empty, but now that it has been sitting full for a while it could have shifted a mm or so)...

Thanks sbash. As you can see from the post I just made, I've drained and broken down the tank this morning. So I'm not able to check the level of the tank full after it has been sitting for a while. Just for future knowledge, how would you go about leveling a tank when it is full?

 

[sbash]

Thanks sbash. As you can see from the post I just made, I've drained and broken down the tank this morning. So I'm not able to check the level of the tank full after it has been sitting for a while. Just for future knowledge, how would you go about leveling a tank when it is full?

Drain it... lol...

Realistically, it should be fine to check the level empty now (as it would still be settled from the weight). I just thought I would mention it as a possible cause and something to be aware of that can cause this sort of issue. That said, this is a small tank so it is probably a non-issue...

I have only had this happen to me once (on a 4' 60 gallon), and it likely had to do with minor bowing or twisting on the 2x4s, as well as a slightly uneven concrete floor... So the plywood would have settled into the framing a bit once the weight was on it. I drained it, adjusted the frame the 2mm it needed and it was fine...