Vannie toy -- possible?

[mikev]

Is possible to construct a safe tunnel of strong current for fish to climb against?

Specifically, Vanmanenia seems to have a strong desire to climb against the current. This desire brings them into the HOB filter (body damage) or into the powerheads via the outtake (certain death). Protecting the dangerous devices against Vannie instincts stopped the suicides (I had several before I understood what is happening:cyr:), but ---I think--- denies the fish what they clearly want to do.

(I'm likely wrong, but I have a feeling that going up the current is natural for them, with possible some similarity to salmon migration.)

So I wonder: is it possible to build a tunnel, say 5-10" long and 0.5-0.75" in diameter that has strong current and is safe for fish to go through all the way?

Can the great construction minds of this site offer a design?

[Martin Thoene]

That's a tiny pipe. I can design something that would acheive that desire in a bigger size. BUT.....right now I have to go out....so later.

Martin.

[mikev]

Thanks, Martin!

Small diameter is because this is how large the powerhead outtake is, and it clearly attracts them (I lost at least 4 this way)...likely this does not matter too much.

Incidentally, this behavior gives a simple way to distinguish the Vannies from disparis: put them into a tank with a powerhead, and the ones that are alive six months later are disparis.