Just a word of advice.
Many many many people will say throw a established sponge filter into a tank and its instant cycled. My experience with this, this is not the case. It will speed up your cycle, but will not instant cycle your tank.
I ended up putting a sponge filter into a new tank (The sponge filter was from an established tank of more than 3 years.). I added drops of ammonia to the tank, Ammonia would go to 0 fairly quickly but Nitrite was thru the roof and I barely had any Nitrate. It took the tank over two weeks to cycle.
When I decided to make my shrimp tank, I tried again using an established sponge filter. After two weeks of having high nitrite, I decided to throw in a bunch of floating plants and start dosing ferts. After a week of doing this, the tank cycled. Frog Bit works works wonders in zapping all the Nitrite in a tank. Not sure if the tank cycled officially or the frog bit simple removed the toxins from the tank. Didn't matter to me, I put my shrimp colony in it and its been running ever since.
What I'm saying is be very careful when you start cycling your tank.