My betta likes to let his fins get sucked by the filter?...

[moonbubble]

I noticed a couple of tears in my betta's fins, and at first I was worried about fin rot, but then later in the day I noticed him laying against the filter without even trying to get away. I tapped on the glass a little and then he finally swam away, but it's hurting his fins.... Why is he doing this ?

[Laki]

It could be that the intake is too strong. Can you lower the pressure in the valve? To get my fish used to the filter I put some pantyhose around the intake valve with an elastic band.

I don't know why your fish is doing it, but I would try to at least fix it so it can't tear his fins!

[DragonFish]

I doubt hes doing it on purpose or he likes it. More then likely he just swims by the intake and the pull is too strong for his delicate fins, so they get sucked in and torn. It would definitely be a good idea to baffle your filter intake. I baffle all of mine just as a precaution now, even with my PKs.

I've been baffling my intakes like Laki, with the foot of some pantyhose and elastic....however, after I had a scary mishap where my fish got caught between the elastic/pantyhose and the intake(which eventually led to his passing), I've started taking small pieces of filter sponge and sticking it down into the intake tube and this seems to work alright.
There is also a prefilter sponge that you just slip over the intake. Fluval makes a nice little one.

[Blue Fish]

I use the sponge method DragonFish mentioned, and then you *know* they can't get sucked up in there.

If you can't find regular aquarium sponging, some of the filters require foam sleeves, and these work *great*. I use them to baffle the outflow on my waterfall filters as well as the intake tubes. They're just the right size, and they were actually cheaper than the aquarium sponging I was able to find at my LFS.