Cycle Question

[cornishlass]

Is cycling necessary when using an already up and running filter? Or is it just for new filters or am I totally off track? I was chatting with my neighbour yesterday and now I am totally confused.

Also said neighbour has a black Molly in a glass bowl, ahhhh poor thing

 

[Joshwainwright]

If you have two tanks and you are simply switching to another, the previous filter can also be moved over without it being re-cycled. The trouble is with moving a cycled filter to another tank is there may be a greater number of fish therefore there will be a greater amount of ammonia which the bacteria may not be able to cope with at first.

 

[cornishlass]

Ok so will I have to cycle? I had a single goldfish in my 64ltr tank who passed after years of ownership (poor chap) the filter had been in their a year (old one decided to pack up one day) so now I have an empty tank. I am taking all out and creating a planted tank for tropical fish. So same filter same size tank, but new water

 

[Joshwainwright]

As the goldfish died, the filter media will have no longer have had a source of ammonia and also died. This unfortunately means that you will have to go through a cycle again. The best way to cycle a filter is by adding household ammonia to your tank and observing your Ammonia and Nitrite levels.

The chart below illustrates what you will see:

 

[cornishlass]

Thank you for that, its only been two days since the filter has been fishless

 

[Joshwainwright]

In that case, only some of the bacteria will have died. You need to get some ammonia in as soon as possible to keep the bacteria alive and multiplying.