I would guess he is about 4-5 inches. I have had him in the 38
gal tank since 1997. He has been a really good fish. He was pretty small when I got him. I treat him with dried krill or frozen. Normally he gets large pellets.
I had a porcupine puffer for about 3 years before the dog that grew to about the same size. He died when my power went out for 3-4 days while on vacation. He was my favorite fish of all time.