Could you be more specific. How did Connoisseur ruin your plants..?
At my normal feeding levels, Connoisseur was unable to grow healthy plants while all the other brands could with ease.
What were the manifestations of the Ruination.? Did you run the Connoisseur at their recommended full strength..? That will kill 'em. Gotta work your way UP with nutes at the onset of use.
I'm not familiar with what 'full strength' means. Connoisseur made up less than 1.0 of my total EC. Total EC ranged from 1.0-1.2 during the flowering cycle.
Truth is, all these compounds contain what is necessary to grow plants.. Why did Connoisseur NOT work, when all the rest did..? Could have been one of your additives.
Not all of the bottles in the hydro store work well in all mediums. Normally, hydroponic formulas contain some split of nitrate to ammoniacal nitrogen, usually it's weighted heavily towards nitrate. Connoisseur contains 25% nitrate with the rest being urea (~20%) and other water soluble nitrogen (~55%). IMO, these are poor sources of nitrogen for hydroponic applications due to their high foliar burn potential. Did I mention they're cheap sources too?
Such a general blanket statement needs backing up. Although I am using Botanicare now, I found Connoisseur to be the best thing my plants ever got. That was in DRAIN to WASTE, but I do not see what a difference that would make.
BOG back at Overgrow got me on Botanicare and I used it for 8 years in promix. Worked great actually, but that doesn't mean I'd be quick to throw PureBlend into my hydro tables.
http://140.254.84.203/wiki/index.php/Water_soluble_nitrogen_(WSN)
A form of fertilizer in which the nitrogen is readily available for uptake by plants, and which provides quick color and growth response, limited response duration and high foliar burn and leaching potential; WSN sources are typically less expensive per pound of nutrient than Water insoluble nitrogen (WIN) sources.
Short thread here at ICMAG concerning Urea in hydro:
http://www.icmag.com/ic/showthread.php?t=220379
Hope this helps.