Could changing the gravel in my tank put me in a mini cycle?

[GirlieGirl8521]

I also agree, the bacteria in your filter should be enough. If you are worried though, you can put some of the old gravel (i wouldn't put all of it ) in a stocking or push some to the middle of the tank and then put the new substrate over it. I did this with my 55g when I changed from gravel to Eco Complete. I moved a couple handfuls of the old gravel to the middle (so you can't see it) and then put the Eco over it. I only had a HOB filter at the time, so I wanted to put my mind at ease by adding some of the old gravel.

 

[mooman]

Agree with the last three posts. Remember the bacteria are not evenly distributed throughout the tank. They are concentrated in areas of high water flow (well oxygenated areas). If you were running an undergravel filter it would be a different story.

 

[tom91970]

It can, but one way to avoid this is to take all your original gravel, and put it in a womans nylon stocking, tie it off, add your new gravel, and set the old gravel in the bag in the corner of the tank. After about a week you can pull the gravel out without ever having to worry about cycling.

This is what I did with my existing gravel. I borrowed some gravel, placed it into two different nylon hoses, and placed that into my tank about three weeks ago.

 

[Mgamer20o0]

go for it and let us know what happens.