Hagen diffusor a death trap for fishes??

[Plantasia]

Last night I picked up a Hagen CO2 system for my 5 gallon cubic tank, set it up and later in the evening one of my rummy noses somehow wriggled its way up the ladder! I don’t know HOW he got up there. It was a bitch to free him because those suction cups are so strong. Has this happenened to anyone else? I’m at work right now, but I’m worried I might come home to find a dead fish or two in the diffuser. How do I prevent this? I don’t see how he could have gotten up there since the back of the diffuser is pretty much flush against the aquarium wall.

As a side note, I didn’t even use the activator/stabilizer packets – they were expired anyway! I just poured sugar to the first line, added a ¼ teaspoon yeast and a teaspoon baking soda, and it started bubbling within half an hour Hopefully, the bubbles will stop escaping the diffuser though -- the instructions say its normal for the first 24-48 hours. Any thoughts on this?

 

[TLH]

I've had Leopard Danio's get down the back of mine before.Just squeezed the suckers to get them off,although I do agree it's a bit difficult to do.I think it helps if you put the base against the substrate so fish can't swim up from below.

I would try to use the old packets of stuff,even though they are out of date,they'll probably still work anyway.On mine bubbles escaped the top all through the fermenation period.It very much depends on temperature and water depth and various other things.Aslong as the bubbles are getting smaller as they travel up the ladder I wouldn't worry.

 

[Lotus]

I've had endlers livebearers and an espei rasbora get in the ladder before. I discovered both before there was a major problem. They seem to keep away from it now.

Yeast (the activator) tends to lose potency after its best-by date, but it shouldn't be dangerous in any way. If you find it's not producing as you think it should be, you can redo with fresh solution.