I've always had struggled with mold in my cat's grass.
Now, I tried growing it in straight tab water, without nutrients. I might add some fertilizer down the road if it lives long enough. But normally this shouldn't be needed, since it only lives for a few days or two weeks max, and the nutrients included in the grains should be enough for that.
I germinated it in a sprout glass, and when the first roots formed, I transferred it into my custom net cup and added some LECA on top.
