@steve: Thanks dude, in the end i went for
http://www.growthtechnology.com.au/psl28/0/oxy-plus, which is good shit. I don't know how but i must of got some on my hands because 2 minutes later they were burning and my hands were fucking covered in little white spots (bleached my already white hands lol). Thankfully an hour or so later the spots just went away. Its 50% and MADE for hydro use
@SCG: I use my local guys nutes as i think they work well and am always one to jump on the "lets support the locals" band wagon. There is ONE guy at the shop who is a complete dick and told me silica was $40 for 1L, but thankfully when i called up again the other guy clarified it was only $15, so same price as the big names.
As for your plants, put them in your greenhouse but run a fan! Fans will promote the plant to harden the fuck up
GOD seems to have the right idea with puttin them a lil lower in the soil too. I think that with combo of a fan should see nice healthy stems. ALSO try use some silica as apparently it makes REALLY thick stems. I bought some the other day but yet to use it so can't comment on it too much.