I dont know anything about hessi nutes or how to use them. If your adjusting your ph to 6.1 thats your first problem. Mix your nutes in a second container of distilled water at your target ppm and let them sit for an hr to fully disolve and balance out, adjust your ph to. 5.7 and wait an hr, if its still at 5.7 then dump your res and fill it up with the solution, the ph will climb over the next day or so, when it gets back to 6.1-6.2 then ph it back down to 5.7. That will give you a good window for nutrient uptake. Like I said, I dont know anything about hessi nutes, what I usually tell people to use for their first hydro run is the lucas formula with either GH micro and bloom or AN jungle juice micro and bloom. Its a simple 5 mills micro to 10 mills bloom for flouros and up to 250 watt hid's or 8 mills micro to 16 mills bloom for 400+ watt hid 's. Its simple, prooven, and cheap, costs about $10 a ltr.