I choose the General Hydroponics Flora nova line. Thats what my hydrodude recommended. He said thats what he sells the most of and the growth was unbelievable.
GH also makes a 3 part line that most pros seem to favor over the nova. Other nutes I have seen on this forum that showed good results. Including but not limited to Advanced, dutchmasters, purablend and something called the lucas formula. The advanced and dutchmasters are nutes formulated just for MJ. So they are going to cost more. Not saying they are better are worse just more bucks. Most consist of a Veg and a bloom nute. That would be the 2 white bottles beside the dip and grow. Them 2 are the only ones you need for growth.They were about 27.00 apiece. The cool bloom is a ripening agent at 0-10-10 only added in bloom. another 30.00. The little white bottle of flouricious plus is a organic additive it is 2-0.8-0.02. 20% kelp. That little bottle was 47.00. WOW!!! I am still missing the florablend, Florashield, and flush. I will get the flora blend when I make the one and a half hour drive to the hydrostore to get worm and bat shit. I thought I was saving money. This new hobbie is killing my wallet.
The bottle has directions on strenths. 1/2 tsp. per gallon for seedlings, 1 tsp. per galllon for early growth, 2 tsp. per gallon for later growth, 3 tsp. for aggressive growth. My plants would never see the 3 tsp.'s unless they were 6 feet tall.
Down side to my nutes. You have to shake the hell out them and they're brown. I can't check the PH with my drops because the water is brown. Nova nutes are like a bottle of mud. If you are confident in your water and keep the Ph around 6.0 and a pre ppm around 100-125(enough to buffer your water to avoid huge PH swings) a small DWC that you have to change the nutes every 3 days (when she gets going) a digital PH and PPM meter are not needed but useful.
I saw the nova veg and bloom together on ebay for around 50.00 on ebay.
Hope this helps. Feel free to ask as many questions as you like. But keep in mind I have only been hydroing for 6 months. All problems I had were created on purpose. It is not very difficult.