American bullfrog growth rates

[clintosaurus rex]

So its been about 5 months for one of my frogs since metamorphosis. The other 4 months. Anyways, when they first became frogs, they were 1 1/2 inches. Now the younger one is just shy of 2 inches, and the older one is between 1 3/4 and 1 7/8 of an inch. The caresheet I got with them said between 1 and 3 years to mature. Now I understand bullfrogs can be as small as 3 1/2 inches, but how can I get them to grow to at least 5 inches? I know genetics and possibly even when they metamorphose impact size, but is there any way? Say maybe feed small frequent meals, instead of the twice a week feedings I give them, or increasing the water temperature. The temp in the water is about 24-25 degrees Celsius. Thanks.

[LazyEyedFroggie]

I believe that increased and more frequent feedings are the best way to promote growth. The water temperature shouldn't need to be increased at all. What are you feeding them and what supplementation's do you use? And, just out of curiosity, why do you want them to grow fairly large?

[clintosaurus rex]

I mainly feed them crickets, with the odd mealworm. As for supplements, I use the Fluker's Repta-Calcium every other feeding, though I might skimp on supplementation, and Flukers Reptile Vitamins about once a month. As for why I want them big, I don't. I just have heard people say there frog was full size in a year ot 2, and since my frogs were still the same size since metamorphosis, I thought I was mistreating mine. Obviously if they have live 4-5 months I think they are ok, but if you have any suggestions please tell me.