Which fish are the best to have in cycle aquarium?

The best option by far is no fish, next best option is snails. After that would probably be Danio's, but doing a cycle with fish is still a lot of work, and a lot of risk even with small hardy fish. More importantly what fis do you plan to own? Since whatever you buy you will either need to find a good home for, or keep for several years you need to consider what you buy before you bring it home. For more detail and answers to most common questions try this link.

http://www.aquariacentral.com/forums/showthread.php?t=64301

Dave
 
I agree with daveedka...a fishless cycle is the best way to go. I know it is hard to wait to put fish in your tank but you have a greater chance of losing fish if you do a fishy cycle. Be patient...do the fishless cycle and you will have a better experience starting out in this hobby. While you are doing a fishless cycle you can plan your tank setup and research what types of fish you would like to have.
 
What size tank are you planning to use? Are you planning on having it planted?

If I knew then what I know now I'd have done my tanks this way:

Bought everything, set it up and started my planting till the tank was full/ half full of plants. Then added a couple of small fish after a couple of weeks.

Plants help eat the ammonia keeping it low during the cycle. With low ammonia you'll have a lower nitrite spike. By adding a couple of fish at a time over a few weeks the bioload stays low and lets the bacteria catch up easier resulting in less drastic spikes.

Read the sticky on cycling, its in my signature under " Most any fish tank problem can be fixed by clicking this link". Scroll down to "Cycling-ins, outs, and arounds " and then scroll down to Plant cycling (sometimes called the silent cycle). The Fishless cycle is also there.
 
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