Comet Goldfish and African Dwarf Frog

Question
Hi, I have an African Dwarf Frog living by itself in an 8" x 5.5" x 4.5" tank with still water. I want to add a really small comet goldfish to the tank but I'm not sure if it would be safe. If it isn't safe, then I have a bigger 12" x 7" x 6" tank, but I'd really like to see if the smaller tank works because I like it a lot better. I'm sorry I don't know how many gallons that would be. I also usually clean the tanks thouroughly once every other week, but change about 30% of the water at least once a week.
Thanks!

Answer
Hello Ashley,
You would be better off putting a few neon tetras in with your frog. They are more compatible (being that both the frog and the tetras are tropical and prefer heated water). Also, comet goldfish - while they start out small at the store (because they are babies) - actually grow to over a foot long in length and your tank will be much too small.