How High EC did you run to stunt? 1000-1800? peak?
it really depends on what type of system you are growing in... some systems can handle a higher EC than others... Recirculating systems can handle a slightly higher EC , and dtw and soil grows take a lower EC... and the brand of nutrients seem to make a difference as well imo.
My set up is pure Canna Coco drain to waste passive hydro system, so that is what my advise is based on?
during veg i would say anything above 2.4 (1200 ppm w/ a hanna or .5 calibrated meter) may be counter productive and that may be pushing it depending on what brand of nutrient you are using...
for bloom, i would say 2.9 is the max, in my experience, you dont need to increase the nutes very much in bloom, you just need to change the NPK ratios with a slight increase in EC during weeks 4, 5, and 6... then for week 7 and 8 i cut the base nutes way back and just roll with my additives for the most part until the final flush.
But if you have a recirculating hydro system then you may be able to go as high as 3.5 - 3.8 for both bloom and growth. for the low end of what is workable, i would say 1.7 EC is the minimum you can get away with without problems.
i know some people will say 2000+ ppm (4.0+ ec) is okay in certain systems, but most botany books will disagree, and i believe it takes a rare strain to absorb that much nutrients.