I have been using this site for Betta information for quite some time now, and have finally joined the community with a question in mind.
A bit of preliminary information about my setup.
I have a male Betta in a 2.5 gallon tank with two ghost shrimp (happily living together for about 3 weeks now). It has a whisper 3i filter, as well as a HT10 Tetra heater (which keeps it at a constant 76-78 degree temperature). It also has a silk plant in the background, a plastic plant up front, and a little circular cove that he loves to hide and sleep in. I do regular 50% water changes once a week, as well as keeping feeding to a minimum with 2-4 pellets everyday, with the occasional snack of 1-2 freeze dried blood worms.
I believe I already know the answer to the question, but a few extra opinions can never hurt. I have recently noticed my Betta's tails beginning to rip, between the spines, and there is no discoloration or hints at fin rot or other fungal/bacterial diseases. I believe the cause of this problem is the plastic plant, because as of recently I've noticed him hanging around it and swimming through it more often than he has in the past. I was planning on going to Petco (where I also work), and replacing the plastic plant for a couple smaller silk plants and see if that does the trick. I have been monitoring levels with the 5 in 1 test strips and everything is pretty much perfect as far as that test goes. I will also be purchasing the API liquid ammonia test kit, because it is definitely better to be safe than sorry on that account, especially with the tank about as stocked as it can get without being overcrowded.
I just wanted a second opinion and if anyone knows this to be a common cause. It isn't anything major, just the tips of his dorsal, caudal, and anal fins. Behavior is as normal as ever, always hungry for his daily feeding and constantly swimming around the tank like he owns the place. After all, he sure does.
Here is a link to the plant for anyone who needs a reference:
(it's the pink one on the left of the image)