Tightest Schooling Fish

I'll take my SLR into work to get a good picture of my harleys. I've been meaning to do that for a while anyway. lol.
 
If there isn't a threat to the school, they'll go wherever they want. Add a predator and any schoolers will bunch up.. Safety in numbers, and all that.

This makes perfect sense but I have to say that my rasboras are always together, never are they at all ends of the tank. They are always in a group together. Now I've only got a 10 gallon so that may have something to do with it.
 
Ive had red eye tetras in the past and they are very tight schoolers. They do however grow larger than most of the smaller tetras and can get very nippy at times. Glass Cats are great schoolers but lack color and mine used to just sit and hover in the filter current, they were cool but not terribly exciting.
 
This makes perfect sense but I have to say that my rasboras are always together, never are they at all ends of the tank. They are always in a group together. Now I've only got a 10 gallon so that may have something to do with it.


Rasboras are a good schooler, but in a bigger tank, they'll tend to wander a bit. Anything will, without a proper threat in the tank. Throw in a big angelfish, they'll be holding hands in no time. (no, I don't mean to put a big angel in a 10g tank...)
 
I currently have 6 harleys in my 46. Always together. I have noticed occassionally that one will venture out but he either quickly joins the rest or the rest track him down. It's quite comical to watch if I must say. And of course the Rummies (I call them nascar fish). When I had em, they too were tight.
 
i have 10 harlys in my 20g and they are pretty much all over the place. they spread out quite often and do this thing where the swim to the side of the tank the filter is not on, then they zoom toward the current from the filter's water output and kind of ride the wave. fun to watch, but not really tight except for 5 minutes when i turn the light on in the tank. very very active though.
 
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