never used a 2liter before. would probably make a great green house for sprouts if you were growing in dirt.

seen a system that used 2liters for the grow pots. think it was an ebb n flow. looked complicated and troublesome. if your going for a cheap system you might just want to use dirt in the mean time til you can decide on a good hydro system. drip systems are fairly cheap and easy to set up, ebb n flow in nice too. hope that might help.