/dev/root fills up continuously

Hello and good evening

.my English is not that good and that’s why I let my german text be translated by Google

First of all … I am totally new in the field of raspberry and Linux and that’s why I have a ready nextcloud images installed on my memory card

But I found that slowly but constantly my / dev / root fills and I just do not know what I can do there (because I have no such right experience)
Have a 2 tb plate connected and the appropriately formatted sodas there synonymous my pictures will be saved …

My memory card is a 16 gb SanDisk Class 10 and I have already expanded the card.

But after the expansion / dev / root was at 16% and now at 24% …
if this continues I can soon make everything new
because where I forgot the card to expand there was 100% final and nothing wanted more …
And now that everything is going so well, I do not want to do it all again …

I hope you can help me

Greez Chris toph

You already posted and got answers here: