Clear Bumps on New F8 puffer tail left side...please help

[FirstTimePufferPapi]

Recently got my figure 8 puffer. Slowly changed him from his 1.004 water to 1.008 throughout the last 3 weeks since I've had him. I just noticed today that he has this small clear bubble-like protrusion on his tail on the left side. He's swimming around the same and eating regularly. I checked his pH, nitrite, and nitrate levels and they are safe. He is in a 16 gallon tank with argonite sand, aeration stone and a filtration system with 2 filters currently in it to help with his messy eating. He gets fed a mixture of blood worms and muscles/oysters. I make sure to watch him for 2 mins and once his belly gets big I clean up the extra food.

I'm new to this and I just want to make sure I'm doing all I can to make sure he has a good life. Any info helps and if you need more information just ask. Thank you for the help!

Ps:once I figure out how to change my photo size to be able to fit in here, I will post it so you can see the clear Bumps

[Pufferpunk]

Yeah, it would be nice to see the bumps.