Will bacteria die in H20 change?

[spudaddy]

Quick questions! If it takes me 2 hours or so to do a water change on a 75 gal reef setup will the bacteria in my bio balls dry up or die? Will I have to cycle all over again? Also - if I tear down a 55 gal. tank with a W/D on it that was a HT used w/ copper for a month - remove all the water and substrate and rock and replace with new material - will the tank still have copper in it? Will I have to cycle again? Thanks!

 

[mr . salty]

I don't see how it could take two hours to change water...But two hours is a long time out of water,and some bacteria would most likly die.And the copper tank may have copper in the silicone at the seams.The only way too know for sure is to fill it with saltwater and test it for copper in a couple days...