Fluval U1 clean & clear

[hypez]

I have just bought a Clean & clear cartridge for my Fluval U1. The center media in the filter is twice the size of the clean & clear cartridge. Do I replace the whole center media with this cartridge or should I cut the center piece in half and place this on top?

This is a photo from google, as you can see the clean & clear cartridge is pushed in the top, however I can't tell if they have fully removed the center piece of foam or just cut it in half

 

[hypez]

This is a photo from google, as you can see the clean & clear cartridge is pushed in the top, however I can't tell if they have fully removed the center piece of foam or just cut it in half

https://www.allpondsolutions.co.uk/SiteFiles/Handlers/Shared/ImageSizer.ashx?image=%2FAllPondSolutions%2Fmedia%2FSiteImages%2FProducts2%2FFluval%2FU%2520filters%2FFluval-U-flip-top-2.jpg

 

[J.Mcpeak]

What is the centre media?

If it's just a sponge, whatever is easiest......

If it serves another function (eg carbon pad) keep as much as possible.
(Although dividing in half would give two equally useable pieces.)

Disclaimer, I have no experience with this filter or the insert in question.

What is the purpose of the cartridge?
You may not need it. Quite a lot of things for sale are not necessary and are merely money making units to keep the manufacturer in business.

Filter sponge, filter wool, ceramic or similar function biological media. That's about all you need in a filter unless it serves a special function. Eg peat for acidification.

Even carbon is only really needed in very few situations.
It is perfectly possible to run a successful tank with only the basic sponge in an internal filter.