water level in DT rises and drops

[SeeFu]

Does anyone have the water level in their DT rise and lower during the day? I ran into a problem where the water level rised in the DT which caused the sump water level to drop causing the ATO to activate. Then the DT level dropped causing the sump to rise which made my skimmer go nuts. I've got the return pumps set on constant speed, I just acn't figure out why it changes so much throughout the day.

 

[huckjai]

Maybe the return pump started pushing more water for some reason? Or something got clogged the drain? Maybe the skimmer pump was pulling in more water for some reason? If the skimmer pulls in more water that would usually lower the sump level and cause the ato to kick in.

 

[SeeFu]

its definitely not the summer sucking in more water. sometimes i'll walk by the tank and i'll instantly know that the water lvl in the dt has risen. the pumps just 3-4 months old and it just goes up and down all day.

 

[Tastee]

Is your return pump AC or DC?
AC pumps will fluctuate with your mains supply so aren’t as consistent in their output as DC pumps as I understand it, particularly if your local supply does vary during peak load times.

 

[pdxmonkeyboy]

What kind of drain are you running? I would suspect that one of the drain lines is not fast enough. Water level rises in the overflow until it spills over into the emergency drain..

 

[SeeFu]

Is your return pump AC or DC?
AC pumps will fluctuate with your mains supply so aren’t as consistent in their output as DC pumps as I understand it, particularly if your local supply does vary during peak load times.

I run 2 DC pumps

 

[SeeFu]

What kind of drain are you running? I would suspect that one of the drain lines is not fast enough. Water level rises in the overflow until it spills over into the emergency drain..

herbie drain w/ a 1.5" main drain and a 1/2" emergency drain. I do run the emergency drain a bit above the weir gates. I never liked running it at weire level because at certain times I could hear the water passing through the weir grates and dropping into the overflow.

 

[ccombs]

I don't know about your set up, but if you do an automatic water change and have an ATO, if anything stops working or is miscalibrated, you can end up with some problems, I just had to deal with that myself.

 

[K7BMG]

Pictures of the system will help here.
But I dont think you have the pump, drain and water level properly tuned yet.
Is your sump under, next to, or in another room?
Are you using ball or gate valves?
New or older system?
Have the drain line(s) been checked for any obstruction?
As you say it varies throughout the day, are you sure you dont have a critter running paths and temporarily blocking the drain?
Is this a DIY tank? I suspect it is with a 1/2 in emergency drain.

 

[ca1ore]

herbie drain w/ a 1.5" main drain and a 1/2" emergency drain. I do run the emergency drain a bit above the weir gates. I never liked running it at weire level because at certain times I could hear the water passing through the weir grates and dropping into the overflow.

If your emergency is really 1/2” (and not a typo) and you run it above the slots in your weir then that’s your problem. A 1/2” open channel will have so little capacity as to be almost useless. Any kind of slight variation in the siphon will mean level variations because the emergency won’t be able to adapt.

 

[pdxmonkeyboy]

If you have a pipe above the weir level.. then there is your answer.

Your water elevation should never go above the weir.

 

[Auquanut]

You don't happen to be using an eFlux Current DC return pump are you? They're known to fluxuate. I have one as my backup return, and it does that. It's very noticeable.

 

[User1]

I believe @ca1ore hit it already as I was thinking the same thing when I read that. I'm not sure why you have different size plumbing unless this is converted somehow. All lines should be the same size. For example I have 3 drain lines each at 1.5" and 2 return lines both at 1". This way primary, secondary, and emergency are all the same @ 1.5". The return lines are both the same @ 1". Everything is happy and consistent. Also, why is your emergency even running? It shouldn't be in normal day to day operations.

As far as display tank water level something is blocking it. I've seen this in my tank when I was alternating flows between a pair of return pumps. I was trying to get fancy with simulating high and low tides. There was a time when they converged and I ended up draining more than the two returns put back. In any case I would look at:

When was the last time your return pump was cleaned
Anything that may be blocking or reducing flow
Do you really have mixed plumbing, if so can you correct
Any other power heads or water movement pumps that could be kicking on at the time when you notice this
ATO schedule

 

[SeeFu]

If your emergency is really 1/2” (and not a typo) and you run it above the slots in your weir then that’s your problem. A 1/2” open channel will have so little capacity as to be almost useless. Any kind of slight variation in the siphon will mean level variations because the emergency won’t be able to adapt.

when i say running about the weir, I mean above the bottom of the weire. basically my emergency drain is about 1/2 way between the top and bottom of the weir slits.

 

[Potatohead]

when i say running about the weir, I mean above the bottom of the weire. basically my emergency drain is about 1/2 way between the top and bottom of the weir slits.

When the level in the display rises, is the water cascading into the overflow, or is the water in the overflow the same level as the DT?

If the latter, this is a problem. You will get varying levels in the DT and you won't have proper surface skimming. You always need some distance between the DT level and the overflow level (emergency pipe), even if it's only 1/4" or so.

 

[SeeFu]

I believe @ca1ore hit it already as I was thinking the same thing when I read that. I'm not sure why you have different size plumbing unless this is converted somehow. All lines should be the same size. For example I have 3 drain lines each at 1.5" and 2 return lines both at 1". This way primary, secondary, and emergency are all the same @ 1.5". The return lines are both the same @ 1". Everything is happy and consistent. Also, why is your emergency even running? It shouldn't be in normal day to day operations.

As far as display tank water level something is blocking it. I've seen this in my tank when I was alternating flows between a pair of return pumps. I was trying to get fancy with simulating high and low tides. There was a time when they converged and I ended up draining more than the two returns put back. In any case I would look at:

When was the last time your return pump was cleaned
Anything that may be blocking or reducing flow
Do you really have mixed plumbing, if so can you correct
Any other power heads or water movement pumps that could be kicking on at the time when you notice this
ATO schedule

the emergency line is not being utilized. what's happening is I set the water in the DT about 1/2" below the emergency drain. sometimes water rises just to the very top of the emergency drain, but it almost never gets utilized. it just kind of goes up to the top of emergency drain and then comes back down and then goes back up.

return pump was cleaned 2-3 months ago,
the mixed plumbing cannot be fixed i run a 1.5" main drain, 0.5" emergency drain and 0.5" return
2 gyres that are set on LTC from maxspect
ATO is just on all day.

 

[Potatohead]

the emergency line is not being utilized. what's happening is I set the water in the DT about 1/2" below the emergency drain. sometimes water rises just to the very top of the emergency drain, but it almost never gets utilized. it just kind of goes up to the top of emergency drain and then comes back down and then goes back up.

The emergency drain should be in the overflow and should be set about 1/4" or so (or more) below the main level of the water in the DT.

 

[SeeFu]

The emergency drain should be in the overflow and should be set about 1/4" or so (or more) below the main level of the water in the DT.

Doesn't this cause some water trickling sounds to be heard? I did this in the past and i moved it up because it was the only way to get the tank completley silent.

 

[Potatohead]

If it's only 1/4" or so it will be virtually silent.

Run the tank without the emergency drain, this will be your normal DT level. Then adjust the valve on the drain so the overflow level drops about 1/4" below the DT level. Then set the emergency pipe to that height. Set the overflow level so there is a very slight trickle going down the emergency drain. You will probably have to tweak it a few times in the first week or so. This is the quietest and most consistent way to run a herbie drain.

 

[K7BMG]

You say you have a 1/2 inch return line from the sump return pump?
That can only push so much water.

If your Gyres are set on LTC. The Gyres can push more water than your return pump can by a lot.

Try this, run your gyres at 10% Straight flow for a day. I bet you will find everything levels out.
When the Gyres are pushing hard they are pushing water into the overflow faster than your return system can put it back raising the sump level.
When the Gyres are pushing low speed and not over running water down the drain the return pump can keep up.

That's why your levels are fluctuating. IMO.

The solution would be to run a 3/4 or 1 inch return line.
I know you say you cant alter the plumbing but you can. Just cap off the 1/2 inch return and run a new pipe outside and over the top edge of the tank.