I used to baby peyote and bottom feed them only. Still had some (too many) lovely adults get completely cunted by fungus gnats. Five too many times. Many cactuses love flood-feeding...

Imagine dry as fuck for ages and then a flood. Gorging is their forte. This watering included a very comprehensive two part hydroponic fertliser. Full dose. #gasp

Will water again in a few weeks or so. Cactuses usually like to dry out between waterings. And this can happen quickly. :)