Changing Over Canister Filters

[FishyWishie]

I currently filter my Fluval Roma 240L via a combo of a Fluval 305 external and a Fluval U4 internal.

Now as im getting much more into planting/scaping I'd ideally like to remove the U4 and replace the 305 with a FX5 to keep same amount of turnover but with just the 1 filter.

Is there a way to do this without flooding the house while swapping the canister filters over ?

Prob dumb question but best to ask

 

[Aqua Tom]

The 305 should be quite sufficiant to filter that tank by itself.