Irfan

This is just a query (for my knowledge).

If there is an established tank (cycled) and you take out all the fishes, then would the cycle break and would the good bacteria die? If the answer is "NO" then what keeps the cycle going. If the answer is "YES", then how long it takes the cycle to break and the bacteria to die and is there any way to keep the cycle and bacteria going (maybe by adding food to generate ammonia).

I hope that made sense.

Regards,

Irfan

aquarist48

Good morning Yes, the cycle will crash if the beneficial bacteria doesn't have a food source (fish food and waste). I don't know for sure how long the cycle will last once the food source has been removed, in your case the fish. Adding flake food might help to keep the bacteria alive, it just depends on how long it takes the food to decay. It may not decay fast enough to feed the bacteria.
You can always place all the media into a cycled tank that does have fish in it to keep the good bacteria alive. That way should you need a quarantine tank in an emergency you have additional filter media ready to go into the filter for the quarantine tank. Or should you decide on a new tank...then this filter media will be ready for that as well.
Ken.

Butterfly

There should be residual food and waste in the substrate (no way to get it all out )so the cycle would last for at least several days to a week but I wouldn't push it much longer.
carol

Irfan

thank you both for the replies. Now for the next question, I would like to setup a two gallon fry tank. Would changing 30% water daily by taking water from an established tank speed up its cycle completiom.

aquarist48

Thank you Carol!
Irfan...the beneficial bacteria is not free floating but it is attached to all surface areas in your tank and filter. The water from the established tank will not benefit the bacteria in the new tank. Increasing the temperature to about 85 (fishless) in the cycling tank will help to speed it up some.
Ken

Irfan

Thanks aquarist48. I've learnt somethine new today. Cheers to all of you for hosting such a good forum. Appreciate your efforts.

Thanks n regards,

Irfan