Emergency Tank Upgrade , Concerns...

[Dskize]

I currently have a 160 litre with 2 juvenile (2-3 inch) Oscars in it , I have a 5x2x2 tank as their eventual home ,my problem is I have to put them in the new tank a lot quicker than I thought , some emergency roof work means I have to move the small tank out of its home ,so my plan is
 
I have part filled the large tank , I'm currently running a FX5 on it and temperature matching it with the small tank.
 
I need to swap the Eheim canister filter from the small tank to the big one once the temperature is correct , put the Oscars in a container and drain the remaining water from the small tank into the big one, shift the wood etc.. .
 
Now the Bio load of the tank will not change (right.?..same fish) , of course there is 4 x the water but will the Eheim running with the FX5 provide enough bacteria to keep the fish healthy until I move the whole lot back into its final resting place , the 160 litre (Eheim) has been running for around 3 years and has very healthy water parameters when tested , The FX5 is brand new.
 
I don't really have a choice but obviously I have concerns.
 
 

 

[techen]

The bioload will not change so long as your running the same filter or moving the media over to the FX5.

 

[TwoTankAmin]

If you have substrate, move that too as well as any rocks etc. there is bacteria on it all. You should be fine, You may get a small ammonia spike but it should not be great enough nor last long enough to be a serious concern. Be safe and test anyway.

 

[eaglesaquarium]

...especially with that volume of water... those small fish won't create a lot of load, so the bacteria should be just fine building up to meet their needs without much concern.