Display Tank water level drop mystery

M

MrApplebee

New member
My tank has been running for four weeks now. (4ft long and 340 litres display tank) It has a pretty basic overflow box design. Two standpipes in the weir, one of which is a bit higher than the other. The lower standpipe has a regulator valve which I have adjusted so that the higher stand pipe always has a very slight but steady trickle of water going into it.

I have a tiny marker that I've put on the back of the tank to mark the level that I set the display tank to. I also have a marker on the return section of my sump to show where I have the water level of the sump set. I have a tunze auto top off also.

I've come home from working away for three days and the volume in the sump is perfect. But the volume in the display tank has dropped about an inch and a half. I've checked for leaks and can't find anything. I also turned all the power off and noticed that the water didn't rise as high up in the sump upon draining as it usually does when I turn the power off.

There's probably a really simple explanation for this but I just can't get my head around it. Any ideas?

Thanks

Mike
 
Just to add, the tank has maintained the levels that I had originally set it to consistently since setting up. This seems to have happened over the last 3 days.
 
There's really only three possibilities: the water is accumulating someplace you're not looking in the tank (e.g., in the overflow box), you have a leak, or lots of evaporation. The first should be easy to rule out, so I'm assuming that's not it.

Has the humidity or air flow changes radically in the area around the tank? Are you showing a salinity increase? If no, it's not evaporation, which leaves us with a leak.

It's sometimes easy for a leak to go undetected for a while, particularly if it manages to channel into the walls somehow. Keep looking.
 
SAT said:
There's really only three possibilities: the water is accumulating someplace you're not looking in the tank (e.g., in the overflow box), you have a leak, or lots of evaporation. The first should be easy to rule out, so I'm assuming that's not it.

Has the humidity or air flow changes radically in the area around the tank? Are you showing a salinity increase? If no, it's not evaporation, which leaves us with a leak.

It's sometimes easy for a leak to go undetected for a while, particularly if it manages to channel into the walls somehow. Keep looking.
Click to expand...

Thanks.

I'm
Not 100% sure what you mean about water accumulating in the weir? The weir is full of water , at the moment it's just barely siphoning down the main stand pipe.

The weather has changed drastically the last few days. But, my top up reservoir hasn't really used an unusual amount of RO water up.

Can't find a leak anywhere. It's puzzling me this. Im a bit worried to be honest. Lol

I can't understand why the water wouldn't reach the second overflow pipe if the pump is still pumping at the same speed and there is no leak. (If there was a leak big enough the effect both the display tank level and the pumps ability to keep up, the system would have ran dry??)

Could it be something with the pump maybe?
 
Water levels can change "some" after oh lets call it "new tank break in" as bacterial slime layers,etc.. start to accumulate inside pipes,etc...
Could have been trapped air,etc... too..
Just continue to monitor it and see how it goes..
 
mcgyvr said:
Water levels can change "some" after oh lets call it "new tank break in" as bacterial slime layers,etc.. start to accumulate inside pipes,etc...
Could have been trapped air,etc... too..
Just continue to monitor it and see how it goes..
Click to expand...

Thanks mate. It's just confusing me as to where the water has gone. I've closed the regulator valve on the down pipe a little more so the display tank level has risen and I've got a steady trickle down the second stand pipe again. I'll keep an eye on it. There's a fair amount of water gone though which is evident from how low the level in the sump is now after the regulator adjustment, absolutely no sign of a leak though. See how it goes, be an absolute nightmare if I have to strip everything down.
 
mcgyvr said:
Well.. the water has evaporated...
Do you have an ATO? or are you manually topping off?
Click to expand...

I have an ATO. The level in the sump was perfect when I returned home today. The level in the display was low.

I have just got the display level back to where it should be by closing the regulator valve on the main stand pipe. So the water level in the sump is now lower than the marker I have on the sump glass to show where the level should be. I'm starting to think it must be a leak....I just can't figure out where it is and I can't fogure out why the auto top off hasn't used anymore RO water than usual.
 
If the water level in your sumps return chamber is lower than the mark, Why is the ATO not filling it back up to the full line? You do have the sensor/float switch in the return chamber right? Set to that full mark.
Maybe the sensor/switch is stuck or bad?
 
Last edited:
Smokey Stover said:
If the water level in your sumps return chamber is lower than the mark, Why is the ATO not filling it back up to the full line? You do have the sensor/float switch in the return chamber right? Set to that full mark.
Click to expand...

Sorry, I should have said. When I new that I was going to adjusting the regulator valve, I turned the ATO off. I have now lowered the ATO sensor to the new water level in the sump. I'm going to monitor things and see how it holds out.
 
Is it possible that there is a restriction in the line from the return pump back to the tank? If the sump is holding a constant level and there isn't a leak, then, at least to my thinking, the most likely reason is that the return flow to the tank has decreased.

jm.02
 
from my understanding. if there was evap that was causing it. it would happen in the return chamber only. you said you have an ATO so if there was evap, your ato would kick on almost constantly to keep up with that much evap. so first one empty would be ato container, then the return chamber, then the main tank/ sump at the same time. but your saying your system is running and the sump levels are consistent so it can not be evap in the main aquarium only. that simply doesnt make sense...

now billdogg comment makes sense to me..

also i thought maybe air in the drains restricting draining potential and it finally "burped" as they say and is now draining at capacity....
 
There is no possible way that the display tank can run low with a normal sump level. The sump would drop. Do you have adjustable standpipes? If one slid lower that is the only way. Even if you did have a mystery leak it would show in the sump running low, not the main tank.
 
Cheers for the replies guys.

I’ve checked the salinity and it’s fine.

After readadjusting the regulator valve last night, the display tank appears to have held its level. Would the air lock in drains explain the apparent loss of water? I’m thinking it would if the air lock suddenly buried and water then occupied the space that the air was taking up.
 
Your running a herbie setup, sometimes you have to fiddle with the valve on the drain. It will not remain constant at all times. Sometimes the littlest variable will affect it.

Mine often times will drain down the overflow until I fiddle with the valve, filter socks plugged up, main tank is slightly higher then it usually is. Fresh sock and I need to turn the valve a bit, snail got down the pipe, fiddle with the valve.

It's the nature of a herbie setup. It is not set and forget like a bean animal.
 
You must log in or register to reply here.

Similar threads

Z
Old Elos 70 - how to raise water level and reduce water noise?
Replies
9
Views
1K
discotu
discotu
Q
Which mini snail for artemia tank?
Replies
2
Views
75
griss
griss
E
Getting back into the hobby
Replies
11
Views
259
Uncle99
Uncle99
E
Setting up new 60 gallon tank. Mixing initial water question
Replies
7
Views
190
Elmareefer
E
K
Fluval Reef 4.0 LED Nano Power Level for 15G?
Replies
3
Views
136
kingyking888
K
Back
Top