I am not saying this company is better than others or offer better prices than other just that they are well respected by small commercial growers. If you email them a guranteed analysis of the micro nutrient formulation they will mix it for $27 per gallon. The last time I inquired they were preparing the solution at a 450X concentration. It can be supplied at a much, much higher concentration. You would need to contact them as to the concentrate they now supply. Realize this however; for a 100X concentrate a typical mj hydro total weight for all micro nutes is just a bit shy of
3/4 of an ounce. Not including the cost of the molybdenum which is only about 0.001 ounces, the most expensive trace element is manganese at
$2 per ounce retail. So for a 100X concentrate were talking a material cost of about $2, plus, the jug, label and labor. All the cost are the same regardless of the concentrate etc the salts. So for $27 I would demand at least a 300X concentrate. To assure that give them a formula three times stronger then required. IE for mj specific the standard analysis should be, Iron 0.10%, manganese, boron, and zinc, should be 0.05%, copper should be 0.01% and molybdenum should be 0.0009%. This is for a 100X, for a 300X you would ask for levels three times those listed above or specificaly state you want a minimum of a 300X concentrate. Consider their cost are less than 1/3 retail for the ingrediants. They can afford to be generous with the concentration. Do not custom order a micro mix that contains calcium, magnesium or sulfur!!!!
http://www.cropking.com/HydroponicSupplies/index.php?main_page=product_info&cPath=264_266&products_id=347&zenid=7c8ea447c5f97d79042fe51914472f92