How to display category and quantity data combined?

[helengreaves]

This is a very basic question - so I apologise in advance...

I have water chemistry data (nitrate etc.) that I wish to display as expanding circles depending on quantity over a map of farmland streams.

All I wish to also do is to also add category data to colour these circles in four different colours depending on the landowner. The final output will be different colour circles (dependent on landowner) in different sizes (dependent on nitrate concentrations).

This - I am sure - is extremely simple, but the videos I have watched so far do not combine the two.

Many thanks in advance!

[DanPatterson_Retired]

Double click on the layer's name and select the Symbology tab...see the image, it may be what you are looking for

[RiyasDeen]

Expanding on what dan has already suggested.

You should land owner attribute as Value fields (where i have used overpass) and set chemistry data as value field using Symbol Size, you should get what you are looking for.