need help with deficiency and possible insect problem

Hey everyone. In my current grow I am growing GHS "The Church" hydroponically, among other plants. I've noticed sort of orange rusty looking burn marks near the tips of some of the leaves of this plant. I know it must be a deficiency of some sort and would appreciate if anyone could help me identify it possibly suggest some sort of treatment for the problem.

Also, on the leaves of most or all of the plants in my grow, I have noticed what looks to be some kind of shiny, sticky looking residue, with black dots (possibly insects?) in the residue. I would rather not have this problem, but I think it may do more harm than good to the plants at this point to treat them.

I have included pictures of a leaf from "The Church that has both the unknown deficiency as well as the possible insect problem.

calcium deff and probally mag deficient too (leafs curling up). to fix the Ca problem you can add some garden or dolomitic lime to the soil, Mg with epsom salts or also the dolomitic limestone most poeple just get a bottle of Ca-Mag and feed, if your concerned about bugs or mildew/mold, while your at the store for the Ca-Mag get some neem oil too, Using neem is not chemical and prevents bugs or fungi also its a nice leaf polish! I use it weekly and to battle out bugs and where i live Mildew.

Is there a way to add calcium and magnesium to my reservoir until I am actually able to go purchase calmag from my hydro store? (Such as epsom salts?)