my betta is in a 5 gallon heated and filtered tank. i got him about 5 months ago. he was in a .5 gallon bowl for the first couple of months. he is very happy, active and eats like a pig. i have a plastic plant in his tank and i noticed the other day his back fin is white or clear on the ends. it doesn't seem to be getting worse and was wondering if this could be fin rot or he is just snagging his fin on the plant. could it be that it is still growing hence the clear?