Optimal levels to indicate a fishless tank is done cycling?

[Anonymous Comment]

I got a 30 gallon tank about three months ago, and I started cycling it about then, using the microscopic shrimp (I forgot their name) to add ammonia. I haven't been doing water changes, because the person I talked to (a professional in the marine fiskeeping business) said not to until I started actually stocking my tank. I want to add shrimp to start my livestock, and I'm going to test my water this weekend. What values should I be looking for to indicate my tank is cycled?

 

[Essjay]

You need ammonia and nitrite to be zero, and nitrate higher than your tap water.

But unless you have added an actual source of ammonia there is no way to know if you have enough bacteria to eat the ammonia made by the shrimps you want to buy. I doubt very much that running the tank with microscopic shrimps, whatever they turn out to be, will have cycled the tank.
The best way to check that it is cycled is to add add enough ammonia to give a reading of 3ppm, then test in 24 hours. If there is any ammonia or nitrite in the water the tank is not cycled.
Bear in mind that the shrimps we buy are sensitive to both ammonia and nitrite.


Edited for spelling