Overflow water level rose by itself on estab tank

[PensacolaReefer]

Hey Reef2reef community I could really use some knowledge here. I’ve had this 80 gallon rimless setup for about 4 years now and the overflow water level rose by itself a few weeks ago and I can’t diagnose the problem. You can see attached in the pictures where the algae growth is and where I drew the yellow lines are where the water level has been for three years. I moved about 9 months ago and cleaned out all the plumbing before I reassembled so I don’t think any pipes are clogged in anyway. Like I said it was working fine after move and reassemble until about three weeks ago. I thought maybe the return pump was getting weaker so I cleaned it and replaced same problem so I bought a replacement pump same pump I’ve been using past 4 years just a new one (sicce syncra 3.0). The tank is cycling fine but that overflow level needs to come down. You can see in the other attached picture that the water level coming into the overflow is above the grates and the grates are open and not clogged. Should I drill the hole out on the top of my durso? I wouldn’t think so it’s been working fine before this...What could have changed or caused this? Thanks in advance for any help!

 

[Greg P]

Do you have a valve on the drain/drains?
I used to get this problem a couple times/year. During a WC with the return running, I'd crank the drain valve all the way closed/open/closed then re-set back to my proper running level.
I could usually feel some crunching in the valve and the critters would flush out

FWIW, changing out the pump would only increase the level. A lower level would indicate a weak pump. Keep that now spare as just that.

 

[PensacolaReefer]

Thanks for your response! I don’t have a valve on the drain and never have and I have never had this problem. I have a flex drain see attached picture. I can adjust the flow of the return pump maybe I will turn it down..that could help lowering the flow on return?

 

[Greg P]

Sure you can adjust the pump output, but it's not going to answer your initial question of why is your water level rising.
You stated you took the plumbing apart and cleaned it, but I can't help but think that there's still something somewhere in your drains causing a restriction.

And, you have a serious low spot in that flex drain. That could be filled with 'who knows what'

 

[Greg P]

Take that flex drain off and check it for 'stuff'

 

[PensacolaReefer]

Take that flex drain off and check it for 'stuff'

Thanks! I lowered the pump output all the way and the flow was so weak but it never went down to that original level. I ran a stretched out hanger down through the durso and can feel it bottom out in the drain line where it makes the turn. I squeezed around the low spot of flex drain and there nothing in there to the feel. The water is pouring through churning out like a spillway into filter sock don’t know what changed. No clue what’s going on must be tat flex drain one way or another I need to probably take it all the way off but like I said it’s flowing through and after the hanger no changes . So weird and thanks for your help

 

[PensacolaReefer]

Thanks! I lowered the pump output all the way and the flow was so weak but it never went down to that original level. I ran a stretched out hanger down through the durso and can feel it bottom out in the drain line where it makes the turn. I squeezed around the low spot of flex drain and there nothing in there to the feel. The water is pouring through churning out like a spillway into filter sock don’t know what changed. No clue what’s going on must be tat flex drain one way or another I need to probably take it all the way off but like I said it’s flowing through and after the hanger no changes . So weird and thanks for your help

When I lowered pump flow the overflow level did go down but no where near where it used to.

 

[Brett S]

With that big down and up on the drain it’s possible that it‘s as simple as some air getting in there and the drain line getting air locked. I’d see if you could try to adjust the hose so it’s a straight shot to the drain without the big valley.

 

[PensacolaReefer]

With that big down and up on the drain it’s possible that it‘s as simple as some air getting in there and the drain line getting air locked. I’d see if you could try to adjust the hose so it’s a straight shot to the drain without the big valley.

Thanks for the reply! I wish I would have done that to begin with however I just recently started having problems it’s ran flawless setup like that for over 3 years not sure what changed. I might have to replumb

 

[Brett S]

Thanks for the reply! I wish I would have done that to begin with however I just recently started having problems it’s ran flawless setup like that for over 3 years not sure what changed. I might have to replumb

If you can get the air out of the line it will probably go back to normal. At least until the next time air gets into the line. I would suggest shutting off the pump, holding the sagging part of the line up, trying to keep it all on a downward slant as much as possible while you start the pump again. Keep holding it until things level out, then you should be able to let go of it.

 

[PensacolaReefer]

If you can get the air out of the line it will probably go back to normal. At least until the next time air gets into the line. I would suggest shutting off the pump, holding the sagging part of the line up, trying to keep it all on a downward slant as much as possible while you start the pump again. Keep holding it until things level out, then you should be able to let go of it.

I’m going to try that tomorrow. I’ll let you know what happens!