Fish One End Of The Tank

[ColR1948]

Just wondered why in one of my community tanks, mostly tetras, they all seem to shoal up at one end of the tank, the filter is at the other end but it doesn't seem to be a fast flow, in fact close to the filter and lower than the outlet the water may be more calm.
It just seems strange when they have a 40" length tank they stay at one end occupying about a 12" of it, any ideas?

 

[sebn]

Just wondered why in one of my community tanks, mostly tetras, they all seem to shoal up at one end of the tank, the filter is at the other end but it doesn't seem to be a fast flow, in fact close to the filter and lower than the outlet the water may be more calm.
It just seems strange when they have a 40" length tank they stay at one end occupying about a 12" of it, any ideas?

Is the heater at the end of the tank they are sticking to? It might be that your heater isnt strong enough to heat the whole tank and is only able to keep that end of the tank at a stable temperature. It's only a theory though.

Seb

 

[ColR1948]

Never thought about that, it is in the middle as it happens but I do have a spare, I might put it in along with the one that's in and see if it makes a difference.
Yes I will make sure it is set at the same temp lol.

 

[Gilli]

Tetras will usually shoal in a tight group at one end of the tank if they are stressed or afraid of something. What other fish do you have with them?

 

[ColR1948]

Hi Gilli, I have 2 Gara Flavatra but they reside in the same corner usually behind a big plant and a rock, I've often seen the Garras come out and swim right next to the Tetras and they don't bother each other, nothing else in there.

 

[ColR1948]

I think I may have found the answer to the fish at one end of the tank, I had a airstone inside a pot with holes in and every now and then a build up of air would fire a large bubble to the surface, I tuned it off and I have noticed the fish are moving around a bit more.
To be honest I don't need an airstone it was more decrotive than anything else.

 

[aquariumart22]

The same thing happened to me! My rummies would stay really low, huddled right in the middle. I turned off my airstones one day for some reason and they were all over. I've only had em for like 3 weeks so I'm happy I figured it out. And I'm happy you figured it out!

 

[ColR1948]

Watching my fish today I noticed something i've never seen them do before, all of a sudden they shoaled up and went from one end to the other in a kind of fast swim so to speak, even the Gara were moving about in a excited state, I wandered what was going on.

Then in my other newly set up tank those fish also were swimming about all over, again in a kind of excited state, then about 10-15 mins later they all settled down, what was that all about?

They may do this a lot but I may not have been in the room at that time and seen it.