People usually grow wheatgrass in giant trays. I like to grow little trays and that way I find it easier to control the freshness. Depending on temperatures and location wheatgrass becomes useless after 10-12 days.
One problem is fungus and mold can grow at soil level [mycotoxins] around the roots and berries. Freshness and quality of the wheat berries is most important. Where possible you want the last years harvest. The older the wheat berries the greater the rate of decay of the germ [sprouting mechanism of the berries].
Even if there are no mold problems the green grass begins to rapidly decay after 10-12 days growing in trays. I find I have less problems when growing in smaller containers or trays.
The next issue [what puts people off] is juicing. Wheatgrass press / wheatgrass juicers cost a lot of money. I cannot afford to buy a wheatgrass juicer. I don't want to buy one. Not being able to do things the way everyone else does creates intelligent innovation.
Forget all these purists who give you rules about what you have to do and how you have to do it. Most people probably cannot afford a wheatgrass juicer. I chop the grass into quarters and blend in the blender with some Ozone water.
Alternatively I use a large mortar and pestle and just like crushing up the garlic and chillies I crush the chopped wheatgrass with a little Ozone water. That way I can control how much water I add. I would rather use a mortar and pestle than a wheatgrass juicer #_+
I rinse the grass roots twice a day .. pouring off the excess water. You don't want the roots and berries sitting in water. It is not necessary to give them tons of water. The green grass stalks actually draws moisture out of the air. I don't have air conditioners .. only an open window.
You can grow little pots or bowls of wheatgrass for the cats .. they love to chew on the grass stalks. I always try different varieties to see which grow best. I tried Organic Kamut that originated from Canada. That turned out a mess. The grains were old and bad quality. The grains sprouted more roots than stalks.
People eat that low quality moldy food [the mold is in the grain when old or badly stored]. When you germinate seeds you get to see the actually life force and quality of the food. Organic does not always mean good quality. Often organic means you pay a lot of money. At some point I have to try seeds from the local and Asian stores.