dont really know anything about the rio, but i did have the mag5 and it worked great. hardly created any heat or noise, very good choice. now that i think of it i had it on my 20L. now its on my buddies 75.HTH
my button polyps love mysis, i target feed them........well sometimes, most of the time i dont. they should get enough food when you feed the rest of your tank, that is if you have anything else in the tank.
if you had a long set of tweezers, you could pinch a piece of mysis shrimp and touch its tenticales. it will grab the food. turkey bastor works also. i use a 5ml syringe with a rigid airline tubing attached to the end, works great for cyclo-eez.
HTH
target feed it and it will really take off. youll want a colony of them before fraging. i target fed mine mysis.
oh yeah ......welcome to nanotank :lol3: