You no doubt can stick with your setup now, Just make sure you are running said bulb for said ballast. Top every node you see and manipulate them so they grow bushy. The node lengths are what you want to look for. The tighter, the bigger the buds.
Yes, 1 plant in an 18gal container with a scrog setup is nice. However he is running a 1000w HPS with a 6x6 footprint and 4ft of light penetration...it's over kill.
600w hps = 4x4 footprint with up to 3 Ft of light penetration, You don't think its still overkill right now?
It would cost you more to buy a new light than veg it for a month @ 600w.
Only because of the how the plant's look now, and your lack of knowledge with LST, SCROG and TOPPING. You could manipulate them to be substantially large and get a bang for your buck out of the 600w. However, I'm a firm believe in the fact that light penetration only goes so far. Hence, Go three feet down from the top of your plant...and everything else is useless popcorn and just taking energy away from the top of your plant.
So it cost's you less than $100 to run a 600w light with the fans to cool it and such?
You veg to create nodes (more places for flowers to bloom) However you could veg into a monster but you are limited to the penetration of your light. The amount of lumens is crucial as you get further away from the light source. They diminish tremendously.
You can wait until next time just to see for yourself and gain the experience. Watch them grow, manipulate them.
Not nearly as much as when I thought you were using a 1000w. Depends on where you live, price per KW and such. You might have peak hours, that I don't know. Yes, Grab some cages, top the plants, tie them. You want to create as many "New Branches" as possible. YouTube is great tool at seeing how people actually do things. Google terms you see and search for videos pertaining to them.