How do you start this siphon?

ILOVEBETTAS

It's Cory Lover's cat!
I sucked it, it started siphoning but the moment i stopped it backed up again.
 
Make sure the end you're sucking on is lower than the level of the tank. I think that may be your problem. Siphons work on gravity.
 
you have to wait until the water is almost coming out the end. Oh and put your fist around the end of the tube and suck through your hand instead of putting your mouth on the tube.
 
It says it has a check valve, so you should be able to hold one end higher than the tank, suck water almost to the end, then put your thumb over the end and sorta quickly put it down into a bucket (below the level of the tank) and remove your thumb. Gravity should do the rest.

I'd think the checkvalve should keep the water from running backwards, making it easier to start. But maybe I misunderstood the description.
 
I've never used anything with a check valve, but I fill mine at the sink, cover the end that will go in the tank with my hand, put my thumb over the tube end (the end that will go in the bucket), then release both when the canister part is in the tank and the other end is lower over my bucket. Since it requires two hands, put the bucket where you want it first!
 
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