Overflow just stopped working

[emm0909]

A month ago my overflow started giving me issues. I thought it was an algae issue up top so I cleaned it up and dialed the pump flow back in. What I didn't realize was that I had the return pump throttled back a lot more than normal. Wednesday night I woke up to my pump running dry and my display filled to the rim. What the hell happened? I shut off the sump and just kept the water moving in the display. When I got home from work the next day I took the overflow apart to find a fat nerite and my six line plugging the way. What a pity.

I had the overflow setup with no angles before and it would allow an overboard fish another chance to avoid death in the sump. Of course the skimmer pump was a big battle but at least there was the option to not get killed at that point. Next time I rework my overflow it's going to have a straight line to the sump.

 

[Gary Majchrzak]

so the critters were in the overflow or a drain line?

what kind of overflow(s) do you have?

advice for any newbies reading this: make drain lines large as practical

 

[emm0909]

It's a Marineland tank with overflow and dorso stand pipe/drain. They were both down the drain pipe. I've got a 90 degree elbow under the tank where things were getting hung up. Been running for almost 6 years with no issues. Well, about 5 with the 90.

 

[tmz]

Had that happen via astrea snail last week in a deep blue with a built in overflow.
Fortunately , I had run ran a back up drain down the second hole in the bottom of the tank which normally is used for a return line . The backup is a smaller hole; A standpipe set an inch higher than the main drain feeds it . I noticed a rise in water level in the tank to near the rim but not over.

I wondered how the snail could have crawled up an under the upside down U in the pipe ; but ,then realized it had moved the stand pipe, durso type, at the base ,tilting it enough to get into the drain hose.;some flakes of coraline built up around the snail plugging the drain to a small trickle . The snail was wedged in.

I tried to take the hose hose off the bottom of the hose barbed bulkhead; a slight wiggle cracked it ; water pouring down. Finally got a new bulkhead and fixed it . It was not fun reaching in under a tank and into the built in overflow. The snail was fine. I use covers on the tops of some of the drain boxes to block light and slow down the wanderers but hadn't on that one until now.

 

[SkiFletch]

This is exactly why I built redundancy into my overflow system. Multiple WIDE diameter lines each capable of handling the entire flow from the return pump. I had a trochus snail somehow manage to embed itself perfectly into one of the drain lines and pinch it off. Luckily my backup drain took care of all the flow. I also designed it with threaded 90's, so I was able to remove the 90, remove the snail (with a damned hammer and chisel it was so stuck) and return the 90 to service

 

[jacksonpt]

This is exactly why I built redundancy into my overflow system. Multiple WIDE diameter lines each capable of handling the entire flow from the return pump.

Agreed. I'm running 2 glass holes boxes, both with 1.5" drains, each one individually can handle more flow than I'm running through them.

 

[SkiFletch]

Yeah, it's not an IF question, but WHEN