Definition of 'Clamped Fins'?

[Velvet AciD]

I'm not quite sure what this means so hopefully someone can clarify.

ALSO, the problem behind the question:

My Zebra Danios (3), seemed to all of a sudden swim to the back-left-top of the tank and hold thier fins very tight against thier bodies. For no good reason. And they've been like that for the majority of the day.

Any reasoning behind this?

 

[Balance]

you defined "clamped fins" in your quesion!

holding the fins very tight to the body is clamped fins....

and if your stll cycling that tank like your sig says, they are probably reacting to an ammonia or Nitrite spike.

10G can fluctuate very wildly during the cycle, but Danios are usually tough enough to survive the cycle, but that betta is gonna be majorly stressed out.
I'd move that betta if possible.....

 

[Velvet AciD]

Ah ha, thank you! So how big of a water change should I do to get my water under control? 10%? 20%?

And Den-Ki has been moved, for fear of him drowning himself trying to kill the filter...

 

[AmazonTankz]

I would go with 20% at the most. This way you take enough out to lower the stress on your fish but do not take enough to badly hinder your cycle. At least that how see things.