ok,i will try answer the question:
1.almost 1 year
2.38-40 cm
3.RTG aro
4.shrimp.yeah,i know it's wrong to feed only one type of food,but my father said it's okay cause 7 years ago we had a 60 cm rtg that live for 15 years and the only food he accept is shrimp,seldomly frog
5.yes,around 40 or 35 % a week.i don't have a pH tester...but recently,i don't know why the water in my house seems to look murky,like swimming pool water
6.no,there isn't any red spot,lice,or etc.it's normal,but just for info.my aro is kinda weird.since i bought him first time,he like to swim in the middle and bottom of the tank,and even sit at the bottom with its tankmates.he likes to sit in the corner and watching someone,but he will swim toward people if someone get close to the tank.
7.never
8.no.for almost a year his tankmates are florida gar,senegal,and datnoid
9.no decorations,i'm afraid if he berserk he will hurt himself into the decor.for the lighting,i think nothing special