General Hydroponics FloraDuo A Mineral Nutrient, 1 Quart

For someone looking to get started, with the knowledge I've gained over the past year, I'd recommend starting with a Kratky grow [0]. It's extremely simple and extremely inexpensive (you basically just start some seedlings in rockwool [1], then when seedlings are an inch or two tall, transplant them into a container with nutrient solution in it. A lot of videos and online articles are very finicky, but from trial and error, the only things I've discovered that really matter are A) the pH of your water (pH impacts plants ability to absorb nutrients [2], anywhere in the range of 5.0 to 6.5 has been fine for me), and B) the amount of light your plants get (suspend your light(s) so you can always keep it a few inches above your plants).

To do any kind of hydroponics grow, you'll need (and you can pick up most of this locally (for far less than on Amazon) at a garden center or hydroponics store if available):

  - a way to measure pH (you can get strips for next to nothing, or an electric meter (~$15 for a cheapo one, maybe $40 for a reliable one))
  - a way to adjust the pH [3]
  - nutrients (I have just used FloraDuo 5-0-6 [4] without issue, 2ml per liter of water has been perfect)
  - a way to start your seedlings (I've used rockwool [5] in a clear rubbermaid bin)
  - lights (doesn't have to be fancy [6])
  - containers for nutrient solution (could be a bucket from home depot with a hole drilled in the top for net cups [7])
  - seeds (any home improvement store with a garden center will have a stand with all kinds of seeds to pick from)

Things that make it much nicer (but are unnecessary if you don't know if you want to stick with this hobby):

  - Timers for your lights [8] 
  - Basically everything in this kit [9] except for the netting, grow bags, and "odor control filters" (unless you want to grow that specific plant with the very particular and easily identifiable odor, and you don't want the odor).

Regarding my own build, the setup I built was needlessly complicated, as I'm an engineer and I tried to automate as much as possible. I made a germination station (with a heating pad and tray [10] with a temperature controller [11]) for seedlings, and I picked an aeroponics setup (aeroponics is a form of hydroponic growing where plant's roots dangle above the nutrient solution and are intermittently sprayed or trickled on; this is approximately the build [12]), and if I hadn't been in my house all the time, I probably would have abandoned it in June (but I'm really glad I didn't, it's been a lot of fun). After I got everything built, it's been maybe 40 minutes of work a week (mostly checking the nutrient levels, mixing up nutrient solution, and harvesting plants). Maybe someday I'll make an even more automated system like this [13] where I don't even have to think about pH level and nutrient solution is automatically mixed and added.

  [0] https://youtu.be/5z0NaYpVHMs?t=7
  [1] https://youtu.be/AMlCdm_yVvc
  [2] http://rodsgardening.com/pH.htm
  [3] https://www.amazon.com/General-Hydroponics-pH-Control-Kit/dp/B017XTFKE6/
  [4] https://www.amazon.com/General-Hydroponics-FloraDuo-Mineral-Nutrient/dp/B004PPY750
  [5] https://www.amazon.com/Rockwool-Starter-Twin-Canaries-Chart/dp/B07KJVQ6T5
  [6] https://youtu.be/lT8acb5WTT0
  [7] https://www.amazon.com/xGarden-Lightweight-Economy-Hydroponics-Aquaponics/dp/B07W9H8ZRH
  [8] https://www.amazon.com/Century-Indoor-24-Hour-Mechanical-Outlet/dp/B01LPSGBZS
  [9] https://www.amazon.com/Spider-Farmer-Complete-Spectrum-Compatible/dp/B088R3JHHD
  [10] https://www.amazon.com/CK64050-Germination-Station-Listed-72-Cell/dp/B000HHO1RO/
  [11] https://www.amazon.com/Century-Thermostat-Controller-Germination-40-108°F/dp/B01I15S6OM
  [12] https://youtu.be/edtYDsMthC4?t=67
  [13] https://youtu.be/nyqykZK2Ev4