Brown Coating on leaves

[venymae]

I have a small one gallon plastic hexagon dirted tank with a play sand cap. Currently is has two sword leaf type plants, one small pond snail, and two river rocks.

There is no filter/heater/anything in it. I do regular water changes and replace half the water I take out with old water from my other aquarium (for nutrients?).

My sword plants have begun to look gross. The leaves are coated with brown. I am guessing this is an algae/diatom? How do I remove it? I am afraid to rub the leaves and kill them, and I didn't plan on adding any live critters. Help???

 

[Fish_Keeper123]

I have the same issue on a plastic plant and some decorations ! It's annoying don't know how to get rid of it

 

[Sk3lly]

Diatoms will go away on their own