Filter change over, how long to run side by side?

[oatfish]

Hi Everyone, I first set up my planted tank with an internal filter which has been fine for the last 3 months.
I put an external thermo filter on the tank a week ago to increase flow/ improve the look of the tank. How long until I can remove the internal filter? There's no hurry but it does look ugly!
Thanks

 

[alto]

Just transfer the media from the internal filter over to your new canister filter (likely done with significant room for additional new media), then ditch your old filter

 

[oatfish]

Ha! Oh yeah. That's a great idea. Thanks