I came across this article, Ive stuck to it for over a month 5.2, even with high nutes at 2.2EC What levels should I maintain for my hydroponic nutrient, temperature, pH and TDS/EC? Added by: MisterIto I follow and highly recommend the following parameters for hydroponic nutrient solutions for aeroponic, ?bubblers?, drip, ebb and flow, NFT, passive, rockwool and wick systems. PH 5.1-5.9 (5.2 optimal) TDS 500-1000ppm, EC .75-1.5 Temperature 68-78f, 20-25c (75f, 24c optimal) The pH of the nutrient solution is a major determinant of nutrient uptake by the plant. If the pH wanders outside the optimum range of between pH 5.1 and pH 5.9, then nutritional deficiency and/or toxicity problems can occur. For hydroponic nutrient solutions used with inert media, keep the pH at 5.2 for optimal elemental uptake. It is at this point that roots most readily assimilate nutrients. These pH and TDS/EC recommendations may seem low relative to the normally suggested range, but are based upon information garnered from "Hydroponic Nutrients" by M. Edward Muckle and Practical Hydroponics and Greenhouses. They both document the low pH resulting in increased nutrient uptake and my experience has shown discernible health and yield improvements at a ph of 5.2 over higher levels. On page 100, Hydroponic Nutrients displays both the assimilation chart for organic soil applications and another for inert medium hydroponics, which depicts the vastly different scenarios (see below). The widely accepted soil based chart is frequently misapplied to water culture applications. His research and that done by others, documented in Practical Hydroponics and Greenhouses, indicate that iron and phosphorous precipitate in nutrient solutions at pH levels above 6. Stay below a pH of 6 by all means to avoid this problem and benefit. The nutrient assimilation rate is further enhanced by the reduction in solution TDS/EC, which reduces osmotic pressure and allows the roots to draw the nutrients "easier". Young, established seedlings or rooted cuttings are started at 500-600ppm. The TDS is increased to 800-900ppm during peak vegetative growth. During the transition from early to heavy flowering, TDS is further raised to 1000ppm. It is then reduced to 400-500ppm during the final 2 weeks of flushing. The plants demonstrate their preference for a lower TDS/EC when running a lower pH by clearly sustaining higher growth rates. The optimum temperature for hydroponic solutions to be is 24c/75f. At this point, most elements are assimilated highest and atmospheric oxygen is most readily dissolved. Although increases in temperature increase the rate of photosynthesis, avoid exceeding the maximum listed of 25c/78f. Elevated temperatures make some elements more available, but reduce the solution's dissolved oxygen capacity, increasing root disease likelihood. Nutrient Availability Chart
Here's a more detailed chart, in the hydroponic range, Mn (Minnesota) is the only nutrient locked out at pH 5.8. I've never had a deficiency when pH is -/+.2 from pH5.8. If i were to keep my pH at 5.2 i would be locking out N, P, Mg, which would be more beneficial to my plants than Minnesota. I would recommend pH5.8 from my own experience, so i won't fix something that is not broken. Maybe it's working for you bro. View attachment 140267 Edit: yours is a good chart as well.
Actually knowhere in that article did it say it was referring to what we grow,although most of it is correct the best hydroponic solution temp. is not 75F. Some types of vegies use this 75F. solution temp and others will grow faster in lower temps.,like our plants at 68F. As far as pH,dif. micro nutes are used at dif. pH and thats why we need to allow the solution to natrally drift to the outside level then slowly add pH adj. solution to bring it to the other side so all micro nutes are used throughout the grow.