There's an eel in my sump!

Mkvc · Jul 17, 2021

A few days ago I added a juvenile chainlink eel to my 150g display tank. He's a little thicker than a sharpie and maybe 10 inches long. He's proven to be a bit of a houdini - I had to tape down the corners of my tank lid cos I was worried he would squeeze out. Today I found him in the rocky section of my sump. It's about the size of a 15 gallon tank.

My best guess is that he squeezed through the slats in my overflow. I could easily catch him and put him back in the display but I think this could be a recurring problem.

Should I just leave him down there until he's too big to slip into my overflow? I honestly can't think of a way to seal off all of those vertical slats...

9975 · Jul 17, 2021

Could you put some foam in front of the overflow slots? I've seen people do that with smaller fish until they grow some

N.Sreefer · Jul 17, 2021

I tried putting foam in the overflow to prevent baby mollies from getting in my sump but I resigned to waiting until theyre big enough not to get back in the sump. The foam or smaller slats will catch all kinds of debris and cause an overflow if I was you id wait until its bigger then add it back to the main tank

BanjoBandito · Jul 17, 2021

I love eels and anemones for this very reason. They give zero stinks about your DT and do whatever they want. A kindred spirit for me as my wife likes to point out.

saltyhog · Jul 17, 2021

Is there a gap between the top of the over flow and the tank lid? I can't see him squeezing through the overflow weir unless the openings are a lot bigger than any I've had on tanks.

I had trouble with wrasses jumping between my screen lid and the top of the overflow. It was a pretty easy fix.

lion king · Jul 17, 2021

Take a pic of the top of the overflow, as @saltyhog mentionex, he likely went over below the top. If this is the case, just cut a piece of acrylic or hard plastic the shape of the overflow, and either a couple drops of super glue or silicone to hold in place.

saltyhog · Jul 17, 2021

I just cut a piece of black egg crate. It filled the space completely. I don't think the eel could move it either.

smlarson72 · Jul 18, 2021

We cut a piece of plexiglass and placed it over the top of our overflow. My snowflake did the same thing twice but once that was placed over the top he quit getting into the sump.

Mkvc · Jul 18, 2021

I’m not home at the moment so I can’t take a picture, but I have a glass Planet Aquarium lid (and no hood) that sits directly on top of the overflow as its main support. There is no space between them, and I can barely lift that thing myself, so I don’t think any eels are getting through there. I’ll double check though

My overflow box looks the same as this guy’s. The slats are on three sides of the box.

So far he’s stayed in the display. Hopefully his adventure was traumatic enough that he won’t attempt it again. Will try putting foam in the slats if he does. Thanks for all of the advice!

Mkvc · Jul 18, 2021

Low quality cellphone pic of the offender:

lion king · Jul 18, 2021

If that's the case and the top is sealed, and the slats of the overflow are wide enough, he will eventually get back through them as long as he can fit. It's just their nature to cruise and squeeze their nose into cracks and crevices. I wouldn't use foam as that will get clogged up, probably pretty fast. You could take 1/4" netting and cover the slats, you can use superglue and a strip of plastic at each corner to stretch the netting over the open slats.