Here is an excerpt on tank cycling:
"The nitrogen cycle is a chain reaction in nature resulting in the birth of various types of nitrifying bacteria, each with their own job to do. Each new bacteria born consumes the previous one, and in turn gives birth to the next bacteria. The three components involved to make this happen are ammonia (NH³ or NH³+4), nitrite (NO²), and nitrate (NO³). In general the nitrogen cycling process usually takes about 30 days, but there is no exact time frame for this process to complete its task, as each aquarium is different. Factors such as how many fish, other livestock, and organic matter is present in the tank can vary the completion time, one way or the other."
So based on this info as long as you have a sand bed where the bacteria can live, and this rock doesn't make up a huge portion of your rockwork, I wouldn't worry. I've never read anything on how well bacteria can survive under varying salinity condidtions. If the mantis didn't come out after a few minutes, I doubt he will. They can be pretty tricky. Are you sure he didn't slip out as you were removing the rock? I'm assuming you didn't add any salt to the water from your post. I've read that high salinity water will cause them to exit the rock very quickly as they try to find lower salinity conditions, but i would guess the opposite would work too :notsure: The major concern would be killing off a major portion of your bacteria poplulation.
