Closet Grow not working! Need some tips

I started a closet grow in an aerogarden, I got two real pretty plants (Russian Rocket Fuel), which I didn't really know how I did it because I just put em in and used the aerogarden nutes. I wanted better nutes so I got Flora Nova Grow set. I read the directions wrong and before I figured it out my plants were dead.

I started another one, using the Flora Nova nutes, but no PH tester, I think this is where I went wrong on this one. I got about 8 weeks into it, it was looking great and it just got droppy and died.

Now this is my Third Grow attempt. I am sick of my high dollar seeds dying. I read everything I can find. I started two seeds again in the aerogarden. I read that the lights for the aerogarden were crap for what I wanted so I bought a 400w HPS system. When the seeds had a good set of roots formed I started the HPS Light and just didn't use the light on the aerogarden. I figured since I wasn't using the lights I would create my own containers that do what the aerogarden did. I Made two 1 gallon containers and just put the plastic net thing in those containers. I have been using distilled water, I have been testing the PH everyday, I have an Air pump in both of them and I have been giving 1/2 tsp of Nutes 2nd week (thats what it says to do), One of them is doing great, and one of them is droopy and honestly almost dead. What can I do to make sure the other one doesn't die. how can I bring the other one back to life? Any tips would be appriciated.

 

I will double check it for now on, it might have been to high, since it was a home made container I wasn't sure how full to put it.