The Rules To A Cycled Filter

[loveforfhishies]

what are the rules.. i know it has to cycle and be able to stand a certain amount of fish.. but what will start the cycle over and what will not..

my brother wants to clean his 10 gallon and replace all the gravel ( fully drain the tank ) it will only take about an hour but what are the rules to a cycled filter.. will this restart the cycle if he takes all the water out and puts new gravel and water in within an hour?


hes going from a tank stocked with 1 danio, 1 malawi, 2 guppys.. and hes goin to replace them all with 2 puffers... so does that mean the filter will just slow down to the point where it only has to work for 2 fish or will that start the cycle over by changing the fish amount?

 

[n3ont3tra]

Well, I think puffers are pretty messy fish, so not too much bacteria will be gone, if any. The beneficial bacteria (BB) will change to suit however much ammonia is in the tank, though.
The cycle will only be restarted if he has an undergravel filter and no other kind of filter (ie hang on back). Very little, if any, BB exists in the tank water, so changing that will only rid the water of nitrates, nitrites, and ammonia.

 

[loveforfhishies]

so as soon as new water and fish are put back in the tank. BB will start forming again and keep the filter where it left off?

 

[n3ont3tra]

I would try to keep the filter moving, as long as water is running though it the BB will be okay for a while.

 

[loveforfhishies]

i have a 20 gallon tank... its on the ammonia part of the cycle right now which is the begining.. would it be ok to just hook his cycled filter up to a tank that is not cycled and let it run?

 

[DarkSoul]

i think that would work... but then you would be defeating the purpose of cycling the tank....

it is to establish the BB on the filter media so it has an environment to live and thrive in.... it doesnt live IN the water.

by putting the cycled filter on another non cycled tank, you would then be ready for fish i believe... otherwise the BB on the established filter would die off not having anything to eat.

 

[Irf]

If the whole operation can be completed witin one hour your BB will be OK if the filter is left in a bucket of your old tank water. Just make sure you don't leave it any longer. What type of filter does he have running?

Don't forget to dechlorify your new water.

If the new bioload is less than what he currently has then the BB will just adjust to cope. If it is more then the tank will mini-cycle until the BB multiply to sufficient levels.

You could definitely keep the filter ticking over in a tank that is cycling and therefore has ammonia in it. However that would slow down the cycling process in that new filter - only a problem if you think it is. I would suggest though that you rinse the filter with dechlorinated water before using it in the puffer tank.

Irf.