Bamboo shark 750g sump problem

[killemall]

My overflow vents are where my top tank used to stop draining

Today while doing a water change the top drained past the overflow vents and filled up my 200 gallon sump and overflowed.

I caught it in decent time but still 50 gallons of water on my living room floor.

4 hours of cleaning and trying to figure out why this happened and I'm stumped???

I made a video to show you what I'm dealing with.

Please help if you can. I'm terrified that the power will turn off unexpectedly and the pumps will stop and all the top tanks water will go on the floor killing my beloved bamboo shark "Thumper"

 

[SPR1968]

Have you tried drilling some holes in the return hoses higher up, pointing down into the tank (the level were you want it to stop draining)? Or raise/cut the return hoses higher up.

When the water reaches those holes it should break the siphon effect.

Thats what I have in my large system

 

[killemall]

Learning on the fly. I assume my return hoses are the two that go into my socks. Are these two hoses where the water drains from the top tank and into the sump?

If so that's atleast a starting point for me to try and figure out what's going on.

It always worked fine till today. So I'll try to see if a simple solution is available before I start drilling ECT. But please and thank you for your advice this far

 

[Hypan]

Your return are the hoses/ tubing pumping water back into the tank. If you shut off the return, your water will start a back siphon down the return lines, through the pumps, until the tips of the nozzles in the tank are exposed to air breaking the siphon. So, if your return line nozzles are 6” below your overflow teeth, and you don’t have a Siphon break. Then your tank will continue to drain 6” past your overflow teeth as water back flows through your returns through your return pump and into your sump.
you can either drill a small hole somewhere up top, usually on the inner bend of the elbow that comes up and adapts to the lockline out of your overflow, or get your water nozzles closer to the surface so they break the siphon before they fill the sump.

 

[fishguy242]

agree raise your return jets , also drill holes in each one , 1/8" holes just below water line level when tank is running.

 

[killemall]

Thank you gents. I'm just happy you say it is possible for the water in the top tank to go under the teeth without there being a serious problem.

It always worked fine before. So this gives me hope that it's not broken and I just have to keep messing with the valves ECT.

 

[Hypan]

You need to fix the depth of your returns on the tank itself or drill relief holes. The water will drain until one of the output nozzles on the return in the tank is exposed to air.
you did say it worked before. Do you have anti siphon holes and are they just clogged? Have you messed with your returns in the tank and pushed them further underwater?

 

[Lost in the Sauce]

Siphon break holes IMHO are a must. Siphon break with a one way check valve above the return pump is best practice.

Raise the return lines in the water to have them as Shallow as they can be, while not pulling air from the surface.

With a system that big, small errors can be a disaster. Planning in redundancy is crucial.

 

[killemall]

Thank you. I never even thought about that. My 2 and a half foot shark definitely bumps into them from time to time while searching for food.

I will adjust those and test.

I'll be back with the results.

Thank you for help so far.

Thumper means the world to me

 

[Reef Jockey]

agreed with raising your return jets or at least drill a hole just below the water line for the siphon break. That is a must

 

[killemall]

Hi gentlemen.

Nothing was making sense to me and I spent a good 5 hours under the tank..

Then Hypan sent this picture

That's when it finally clicked for me...the most simple answer that I overlooked.

I adjusted them and now everything is fine.

I see why it's recommended to drill a hole..

At anytime they could lower them selves slowly or my shark could bump them down and presto...

Overflowed sump again.

But if I drill the hole..

Never an issue.

A huge THANK YOU