Hi, I have a young Piraya, hes about 5.5 inches now. Hes grown about 2 inches in the 4 months Ive had him. Is that average or slow? Also, he is insanely skittish. If you sit near the tank, and he sees you blink? He darts around like a nut. This is my first Piranha so, looking for someone thats raised these before. His water is perfect, its dim lit, and he has plenty of cover. Including a slate cave. Thank you in advance!