Some frogs actually shed daily, so twice a week isn't that much. It really depends on the frog and offcourse, on us catching them. It's great to see your frogs are doing great and lovely pictures!
I see. I caught him shedding twice. I changed the water like 5-6 times tho. There might have been more in there. I have "frog water" in a 2 liter bottle next to them now