Hello studentB I hope things are well in England.I also own a greenstar2000 and really like the juicer.When I juice wheatgrass I use a little olive oil to keep the foam down to a minimum.I grow inside and outside when the weather is good.About the juice seperating,that happens to everyone.I wouldnt recomend keeping it in the fridge over a couple of hours.Freezing it would be better,I freez my juice for convienance.I juice 5-7 times a week and that involves a lot of work and time that you obviously dont have.Fresh is always best but life can make it difficult with time constraints.I like sunwave fullspectrum lights,A bit pricey but well worth it.You can check them out at sunalux.com.You should check out greenhouse web sites for more info on lights and there applications.Farmtek.com has some neat growing equipment,shipping would be a bit much but you can get an idea or 2 from there site.When it comes to growing mediums experamenting with differant composts and peatmoss can make a big differance in yield.I am getting 10onzs a flat of wheatgrass and 12onzs a flat of barley,in a 21-11 flat.Keep your grades up and happy growing!!