Plant tearing betta's fins?

I've got a betta and what I believe is Ceratophyllum demersum - you can see it here: http://www.tropica.com/productcard_1.asp?id=021

Edit: Seems this is commonly called Hornwort.

Today I showed the betta a mirror to get him to flare and saw that his tail was split/torn down the middle a ways (a little more than half way) and his lower fin looked a little rough at the bottom edge (not sure if this is any different from when we got him, but I'm sure his tail didn't have a problem before).

Is anyone familiar with this plant? Could it be the cause of his tail problem? Is it too stiff? Or should I be looking for other possible causes?

You can see the tank here: http://www.lizmcguireonline.com/6g.jpg

I'm pretty sure the other two types of plants aren't the cause (they're very soft). He has no tankmates (except a few small snails which came in with the plants)

Should I medicate (if so, with what) or just keep an eye on him?

6g tank, pH 7.2, ammonia 0, nitrite 0, nitrate 15, temp 81F, flourite substrate

Thanks,

Liz

Is that what the plant in the front left corner is - a crypt? (like I said, no labels and the remaining staff weren't sure)

He's been in the tank for 2 weeks and we had him for 2 days before he went into this tank.

I'll see if I can get a close-up of his fins - he doesn't like to hold still!

I'll keep an eye on it and see if anyone else replies on the meds before I try them - I'm hoping they're not needed. I'm also gonna stop the filter long enough to check a little tab at the back of it , just above the intake tube - that's the only other thing I've seen so far that is suspect.

Thanks,

Liz

OK, here's three pics - left full size, so please be patient...

http://www.lizmcguireonline.com/bettafin.jpg (367 KB)

http://www.lizmcguireonline.com/bettafin2.jpg (323 KB)

http://www.lizmcguireonline.com/bettafin3.jpg (784 KB - probably the best view)

Thanks,

Liz

PS: From the photos, I think maybe his lower fin is OK, just naturally uneven maybe?

TheMightyQueenPixie said:

It looks like he just blew some rays...happens...Hit it with the melafix and see what happens...If it starts looking stringy or gunky treat for fin rot....

Click to expand...

Thanks MQP. Will get the Melafix today.

Liz

Well, that does look awfully close - in fact, I went to a site where they sell plants and looked through the crypts and there were several that looked similar - I'm just not certain exactly which kind it is! But at least I know the type, and hopefully that's good news - as I understand it, some crypts can do well in low-ish light, which is what I have (8W).

Thanks,

Liz