First grow i did, i foolishly grew 4 different strains, one of each. I mixed up one batch of water based on the bottle, and shared it around each watering. Only 3 of the 4 survived.
The idea behind growing is that you learn as you do it. You should be thinking that you will look at one strain for now, grow it out, observe what it likes and how it grows and such, and then grow the same strain next time around, you now have a basic idea of what you are looking for and what to look out for, be it temperatures or whatnot.
I have a nice number of grows under my belt now, and have worked with multiple mediums, i still would not like to grow multiple strains from one reservoir tank, i have observed significant variations in what certain plants want and use.