Fish Die Behind Filter

[CANicholls]

How can I stop my rummy nose tetras getting stuck behind the filter and dying?  I have an Elite Stingray 10.
 

 

[NeonBlueLeon]

How big is your tank?
 
I have rummy nose tetras, and they are strong enough to swim past my 200 gph HOB filter.  I'm sure the ES10 is weaker than that.  Are you sure the rummy noses aren't dying, then getting stuck on the filter?  Watch them carefully. 
 
How is the color on their noses?  The color on their noses is a good indicator of stress in rummy noses.
 
When I had an Ich outbreak in my tank, the rummy noses were fine even when their fins were damaged from the Ich.  The only time I found them on my filter intake was when they had already died.
 
If they are trying to swim through a small gap behind your filter and getting stuck, then try and make a larger space for them to swim through by putting a piece of gravel behind the filter.  I believe rummy noses aren't foolish enough to get stuck between things (coughlikebettascough).

 

[Shelster]

I have an eheim internal in my 54litre, over the weekend one of my pygmy cories had his head behind it motionless. I thought he had died until I got the net and he wriggled. I carefully pulled the filter away from the glass slightly and he instantly swam to the surface and took a big gulp of air.
He is ok now, but I feel your pain

 

[Lunar Jetman]

It's also possible they're getting ill and then hiding behind the filter and dying there rather than healthy fish getting stuck and dying.

 

[fluttermoth]

With most filters, I would agree that the fish are most likely sick already; however, I've heard this about Stingrays before.
 
Most people end up cutting a piece of filter floss or sponge to squeeze in behind the filter to block the gap
 
I would seriously thinking about getting a different filter, eventually though. The Stingrays look kinda cool, but the space available for media is, quite frankly, pitiful!