I loved Mega Crop on my last grow. Can be a bit tough to dissolve the 1 part in water (I was making a concentrate and dosing that into my main tank - much easier to get an accurate measurement. I was also using Version 1 from a while back) Dissolved in hot water, and shook for a while. Then shook violently again before drawing it up into my dosing syringe for the main tank. They used to ship out a free trial bag of 200g, and that was what I used. Not sure if they're still doing the free offer, but it might be worth a look. And yes, it's made by Greenleaf Nutrients. From their site...
Try 1000g size 75% discount with coupon code MEGACROPPROMO