For a while now I have noticed that my bettas tail keeps getting smaller near the ends before growing out a bit then going back to being short. I have taken the plastic decoration out 2 months ago and just left a piece of wood and live plants and the problem keeps persisting. I’ve recently noticed that he’ll hang and let himself be suctioned to this filter part (it doesn’t bother him, I think he enjoys just being sucked next to it). Is it possible this could be the cause or is there anything else I should be on the lookout for? Thankyou for the help!