How long should I cycle my new tank with gravel from an established tank?

Question

My new tank's been running for about a day so far. There's driftwood and a layer of established gravel from my another tank that has been running for a year and a half.

Answer 1

Funny you should ask this question today. Last night I transferred an entire 35 gallon tank into a 55. The best tool you have for helping this process along is the filter from your other tanks media. put some new media in the old tank and drop the old stuff into the new tank, and you instantly have a pretty decent bacteria colony... I swapped the entire filter when i did it and so far so good...

Answer 2

I did it for 5  weeks but my friends do it for 2 so I say from 2 - 5 weeks.

Answer 3

The gravel really will not do much. As stated before you really need to use filter media from an established tank. I had to do this in 1 day...I had a 55 gallon and upgraded to a 90 but the 90 had to go where the 55 was. I transfered everything and about 75% of the water and then ran the old filters on the new tank. My tank never cycled doing this.

Answer 4

You have to check the ammonia, nitrite and nitrate levels to determine how long you need to let your tank cycle.  And if you don't add an ammonia source to your tank, the beneficial bacteria will die off, and it won't make any difference that you used established gravel.

If you have 0 ammonia and nitrites, but are registering 10-20ppm nitrates, you could add a fish or two right now, as long as the temperature is stable.  and then, keeping an eye on the ammonia level, add another fish or two/week, until you are fully stocked.