The new Eazy Drain™ Reservoirs use a gradual interior slope to allow the solution to drain completely without manually tilting the units. Designed to be used with a bulkhead fitting and on/off valve- the Eazy Drain™ makes maintaining your hydroponic systems hassle-free. The Eazy Drain™ also includes molded volume markers in gallons and liters so you'll always know how much solution you have left.