Refill Delonghi filter granulate

Hello,

i would like to save waste and money and refill my delonghi water filters. I have also found products for this:

https://smile.amazon.de/dp/B00K7B7AIM

and

https://www.ebay.de/itm/Nachfuellset-Filtergranulat-pass-f-DeLonghi-ECAM-ESAM-Wasserfilter-DLS-C002-/221665992125

Can you recommend a product in particular? I am not sure to what extent the products mentioned are harmless to health and effective.

I don't think much of the whole filtering thing.
If you don't change the filters in time, you'll have a bacteria and algae swirl very quickly
.

Honestly, how often do you change the filter? Do you clean the water tank in between

?
I prefer to descale more often with a high-quality descaler.

So simply remove the filter completely?