[Lexus]

I wouldnt mix goldfish with tropicals. I did once and the goldfish was a pig and would eat all the food. Plus they produce alot more waste and prefer cooler temperatures that your other fish do not.
They reach 14-20" when they mature and can live to be 20+ years old.
Also it is not recomended to keep any type of goldfish in a 10G because of the size they reach. Goldfish should be kept in 20-30 gallons for the first fish, and 10 gallons for each additional fish.

I would suggest either starting over with some different fish or uping your numbers, Tetras are schooling fish and need to be in schools of 5-6+ so are Danios.