I have seen the
nutrient prices some hydro places charge and it is a disgrace as the chemistry is simple.
I am starting my lettuce this week and it is my first hydro project. However we grow quite a bit of vegetables and grain so it's not like we're novices or anything.
Here's what I'm doing for nutrient for the lettuce.
Make a stock solution using 24 oz. Millers 9-15-30 with chelated micronutrients, 5 oz. Magnesium Sulfate. Add enough hot water to bring up the solution to 1 gallon.
Mix 1 cup stock solution with 10 gallons of water to make the finished nutrient solution.
You can get a 25 pound bag of Millers 9-15-30 and a 10 pound bag of MgSO4 from a produce supply place for $50 delivered. This is enough to make 1600 gallons of nutrient.
The resulting solution is balanced for most uses and has the necessary micronutrients in proper proportions. It does not include any calcium. We live in a hard water area so the tap water has enough calcium already. They sell calcium nitrate in 50 pound bags at the elevator for $12 each.
Maybe I'm missing something but it seems like this is a simple yet inexpensive way to mix the nutrient solution. The agriculture-oriented sources give you the most for your dollar.
Steve