The taller tanks make it a bit tough for the Adf's,for they have a need to come to the surface for air on occasion. I keep alot of plants in their tank that gives them resting spots and actually aids them in getting up to the surface too.They'll stop and rest on a plant,and then continue upwards to hit the surface.
My frogs will eat the freeze dried if that's all I have,but they much prefer the frozen bloodworms.
My frogs have actually learned to come to the top to feed also.
The most important thing is to watch them when you first get them,to make sure that they are figuring out the source of food and where it is.I have one tank with three in there.If I'm not mistaken,I have two girls and a boy.The girls are spot on when it comes to sniffing out the food and are nice and chubby,but I worry about the male.He is rather on the skinny side so I have been actually hand-feeding him lately,to make sure that he eats.