Guppie with inflated blobs

Hello everyone!! I was wondering if anyone knew what was wrong with my guppie. He seems to have these strange blobs on his dorsal fin, I’ve done some research and can’t seem to find the answer on how to remove the blobs. I do a 25% water change once per week. His behavior is quite normal too he still plays and roams around with my other two tetras. If anyone knows what is wrong I would greatly appreciate it!

Hi and welcome to the forum

How long have you had the fish for?
How long has the fish had the bubbles?
Have you added anything to the tank in the 2 weeks before this started?

How long has the tank been set up for?
What is the ammonia, nitrite, nitrate and pH of the tank water (in numbers)?