Do I need to cycle?

[jbfootin]

I was just wondering . . . How long can a tank be empty before all of the "biology" dies and you need to cycle the tank again.  I just moved.  The 75 was empty for almost a week and when i refilled it I added the fish (18 peacocks and 8 frontosas - range in size 1" to 1.5" - 2 kholi loaces, 1 raphial catfish and 1 pleco) the next day (wanted to get them out of the tupperwares they were calling home!) with no problems.  The water went from cloudy to crystal clear shortly after filling the tank and sitting up the filter (canister and UG) and has been up and running for almost 4 weeks and the fish look healthy as ever.  Now I am thinking of setting up my other tanks and wondering how long will the gravel and filters keep it's healthy biology?  

If a tank is without fish (full of water with filter running) will the biology die with no ammonia source and need to be re-cycled?

Things that make you go hmmmm

Jay

 

[JWright]

That depends on the specifics of the setup. Bacteria die-off starts almost as soon as the food source disappears, and your tank most certainly went through another cycle when you re-stocked it. The size of the tank helped mitigate that and enough bacteria remained in the filter to serve as an effective seed colony.

Josh

 

[koolkatzfish]

The bacteria can go "dormant" for a while.  It sounds like you were lucky.  Did you do water test during the 4 weeks to see if it cycled?  After all ammonia and nitrites do not cause cloudy water.  

 

[huck]

biology... lol....