Cycling

Question
I am having trouble cycling my 10 gallon tank. I tried using my molly fry but a few of them died. What is a hardy fish that can cycle a tank? Also, is there an easier way to cycle a tank without using household ammonia?

Answer
Hi Alyssa,
Cycling is actually hard on any fish species. Ammonia and nitrite is very harmful to their gills, skin, and bodies overall.

The key to getting through these problems are testing the water daily and taking note of the ammonia, nirtrite, and nitrate levels and doing 50% water changes when the levels start climbing too much or when the fish seem stressed.

I've actually never used household ammonia, so I can't really advise much on that. If I already have an established aquarium, I like to take some of that tank's filter media and add it to the new aquarium's to 'seed' it with bacteria. A very easy way to an 'instant' cycled tank is by running a sponge filter in an established aquarium for a couple of weeks. Then transfer the sponge filter into the new aquarium along with a small group of fish. Sponge filters are such ideal environments for beneficial bacteria that they are colonized in great enough numbers to provide an immediate biofilter sufficient enough to support a group of fish right away. And ammonia problems are non-existent even in a brand new setup.

Molly fry probably aren't the best choice for cycling a tank. Black skirt tetras are very hardy fish, on the other hand. And make good cycling fish. Zebra danios are another species that make very good cycling fish as well.

I do hope this helps and best of luck!
Karen~