Hehe...I see Reptomin as too rich and making a turtle's body function like a machine (like giving super-unleaded fuel to a car all the time). It'll help them grow but not necessarily improve on holistic health.
In the wild, RES and many other aquatics would skim the surface for bits and pieces of floating vegetation, algae, dead bugs, etc...and then supplement with carrion, invertebrates, and occasionally catch something live. I think Reptomin focuses on the best parts of a food...it's like humans eating nothing but super-protein-rich supplements packed with vitamins and minerals all rolled into a bar. I prefer a hamburger today, salad tomorrow, rice krispies, some beer, water, a sushi there, some cola, etc...I personally think variety builds stronger immune systems so the body can handle many random types of food when ingested. Makes me wonder why my grandma's dogs, who were fed nothing but rice and leftover table scraps (bones, fish, fruits, fried chicken, crackers), still managed to live to 13 years much like many dogs who live off formulated diets.