I started this hydroponic rail system about 30 days ago, having absolutely zero experience in hydroponic growing. Thru a few basic steps, I was able to grow some perfect hydroponic lettuce. If I could grow lettuce that looks and tastes this good, then you can do it too. It really is that easy. Note: Some people suggest changing the reservoir every 2 weeks or so. In this situation I did not. However, I would not recommend going beyond the time needed to complete the growth of the lettuce. Before starting a new crop, the reservoir SHOULD be emptied, cleaned, and refilled with fresh nutrients and water. The variety of lettuce is Adriana. It is a heat tolerant butterhead lettuce that I purchased from Johnny’s Seeds. The nutrient mix is a combination of a water soluble 4-18-38, calcium nitrate, and Epsom salt that I mixed at a 2-2-1 ratio, with approximately 8 grams of 4-18-38, 8 grams of calcium nitrate, and 4 grams of Epsom salt per 5 gallons of water. Pour it in, turn it on, and let ‘er rip !