Earlier I made a model of an plater for typography contest and thought that the model could have more potential without the letter. This is the improved model of the original:
I printed this from PLA. Remember to print the indicator with 1 walls and 0 infill for buoyancy.
The inside part should also fit into the M model from the contest if you prefer that. Remember to print the new water indicator.
The earlier contest model, if you like letter “M”:
https://www.printables.com/model/522608-letter-m-shaped-self-watering-planter-with-water-i
The author marked this model as their own original creation.