i mix up about 3 gallons of water and nutes at a time.....which will probably take about 3 weeks to go thru. ive got organic nutes. is it bad to leave the nute water just hanging out for 3 weeks or should i make smaller doses so its not just sitting around for days?
just get a cheap air pump w/air stone and throw it in the bucket w/nutz. and leave it till ya need it. the smaller the air bubbles in the air stone coming out, the better.
Adding the airstone is a better idea. It will keep things mixed up and adding oxygen to the water never hurts.
i don't think having mixed nutes around for 3 weeks is something you necessarily need to do. just reduce your mix by 2/3 and mix fresh weekly.