How Long Before Cycle Stops

[Realtree]

I am planning a major revamp of a fully mature 40G tank
How long Have I got after removing fish before the cycle starts to reverse (bacteria start to die off) ??

 

[Marve99]

I have read a reponse from this question before and believe that with out oxygenated water, the bacteria will die off very quickly (within a day), but will survive in oxygenated water without a supply of ammonia for much longer (from memory I believe a figure of 15% loss of bacteria each day without a source of ammonia)

 

[Realtree]

Therefore would you reccommend that some fish remain in situ in the tank until the last minute as it were ?

 

[cramman]

Is it not worth just adding some ammonia when required. Seems to be working a treat with mine.

 

[Marve99]

How long do you expect the revamp to take?

Also, It is the filte4r which is cycled, not the tank, so as long as you have the filter running wherever it is you are putting the fish whilst performing your revamp, then you wouldn't have any problems

 

[Curiosity101]

How long is the revamp going to take? And what sorta revamp are you doing?

If you're just doing a huge shuffle round, trimming plants, adding new plants etc. And it'll only take a few hours then fish can stay in the tank, I'd suggest doing something like this...

That is my tank last week on Saturday when I did a big decor change. I left them a heavily planted corner to hide in.
I had my filter off for about 3 hours whilst I did the first half, then turned it back on whilst I had lunch(mainly to try to clear some of the sand I'd kicked up), then had it off for another 3 hours whilst I finished.

 

[Realtree]

Cheers for the replies
I was asking as completely revamping tank to a malawi set up
Have fish in it at the moment just to keep cycle going as they wil be rehomed when I do the tank.
I am going on holiday first and was wondering if it would have been possible to rehome the fish before I went.
As I will not be around to add ammonia in a fishless tank I will keep the last remaining fish in it till I get back.
once again thanx for your answers