The one way vent is not needed, and it is acutally preferable to leave them open to the room air so they can get inoculated with yeast and bacteria from your air. Also not necessary to have so much water. Most of us mix the feed/water so that it is about the consistency of thick cooked oatmeal. The ferment works just fine when it's thicker, and saves the extra step of straining it. Check out the FAQ in my signature re: FF.
I figure the oxygen in the air could cause mold. From what I have read mold is not good. I do a three day ferment and the gas build up (co2) was popping the lids