I got this when I did my first couple of jobs. Worked with a spread who told me to cut down on the amount of water when wet trowelling, and thus eliminate any water marks. I told him to mind his own business but secretly took on board what he said  ;D Everything looks much better now Âeveyone must think im mad, when i plaster a wall or ceiling there are light patches all over, instead of be a consistant colour, do you think i could be the fat dry on the surface, maybe im applying 2 much water when trowling up?
yeah like less water or sponge it or six inch brush