But to me "can" and "do" are a bit different and everyone would have their own opinion
The presence of frogs adds another dimension to the pond keeping lifestyle. They add some personality too. Sometimes pond keepers introduce frogs or tadpoles, but frogs always seem to find our ponds on their own too. How do they find our ponds anyway? Frogs are more than just a pretty face and voice that our backyard ponds feature; frogs add to the diversity of species that our ponds support along with our fish, plants, insects, and other wildlife. They help create a more complete eco-system. So what can we expect from these visitor-cum-resident of our ponds? For some the frog is a welcome presence, for others not so much. It seems that it has always been this way.
Change about a third of the water every week. This may be hard if there are a lot of tadpoles andlittle water. You can either run the water to be changed through a net to catch the tadpoles, tossthe changed water with tadpoles into another pond (I do that since I have so many ponds), ordiscard some (to reduce their numbers). Sometimes, I just do not change the water since thereare too many tadpoles, and they survive. By fall, they should be about 0.5 to 1 inch in length. Over winter, they must either be in a pond that will not freeze solid or indoors. If left outdoors,the pond needs to retain an opening in the ice using aeration or a de-icer. I have kept a few in myindoor pond over winter for the last few years, and they do well. By spring, they will have agrowth spurt. By the following summer, they should reach about 2 inches or more in length. They are great algae eaters then and too big for the koi to eat (unless by accident) so they can bein with the koi. After 1 to 1.5 years, the tadpoles will metamorphosize into adult green frogs. The exact time required depends on temperature and food sources. They turn into adults aboutan inch in length and are so cute! By the end of that year, they will be up to a few inches long. By the following summer (two years after they were laid), they should be breeding for you. They only grow up to about 3 inches maximum and do not eat fish (at least, I have never seenmine eat any fish). I have lots of photos of my adult frogs on my various frog pages.
African Dwarf Frogs DO eat fish
do bull frogs eat fish? | Yahoo Answers
The effectiveness of exclusion depends in part on the species involved. Most species responsible for potential or real damage can be effectively excluded from limited areas. Giant toads (southern Florida, extreme southern Texas) or Colorado River toads (southern Arizona, extreme southeastern California) can be excluded from pet enclosures by placing a strip of 1/8-inch (0.3-cm) mesh hardware cloth along the outside base of the perimeter fence. The hardware cloth should be buried at least 4 inches (10 cm) in the ground and should extend to a height of at least 20 inches (50 cm). A similar exclusion fence can be used to control breeding aggregations of nonclimbing species in small, urban stormwater detention basins or to exclude these species from small hatchery ponds. Although treefrogs and some related species will readily climb such a fence, most treefrogs normally breed in seasonal, fish-free waters. In addition, their eggs and tadpoles are readily eaten by fish, so they do not usually present a significant problem on fish farms. There are many species of frogs, found all over the world except in Antarctica. What do frogs eat? Frogs are carnivorous, which means they eat other animals. Small frogs eat insects, worms and snails. Some species eat small fish. Larger frog species eat small reptiles and mammals, like mice and lizards. Frogs do not chew, so all of their prey is swallowed whole.Frogs eat many insect pests. With the exception of fish farms, control measures for frogs are seldom warranted and, in most cases, should be discouraged. On fish farms, the economic damage depends in part on the unit value of the fish produced. Corse and Metter (1980) provided data suggesting that a 350-pond farm that produced goldfish might sustain $42,000 in annual losses to bullfrogs, whereas the same facility might sustain only $12,600 in losses if it produced golden shiners, a less valuable species. It follows that losses might be still higher on farms specializing in valuable aquarium fishes. Some people ask “do frogs eat fish food?” Frogs shouldn’t eat fish food because they require different nutrients to be healthy. However, your fish might try to eat your foods for frogs! You can find the right mix of vitamins in HBH frog food. Pisces Pros has the right HBH products and food for frogs including bulk frog food and frog food wholesale.