Lime green new growth. HELP!

Setup:

- 4L ice cream pail with four 1\2 inch holes in the bottom, elevated inside a larger 4L (4.18L) pail that is totally light proof. It's elevated on bottle caps.
- Soil (Canadian "No-Name" brand, bargain soil... and has worked fine for other plants)
- Watering it roughly 250mL every 2 days, it's in a closet, and hard to reach so I can't do a full saturate, and drain watering each time. I use DASANI RO'd bottled water.

Problem: I have been watching my plant slowly turn lighter and lighter green, and I figured this was simply the nutrients being used out of the soil. When a buddy of mine came down, and noticed it was the color it was, he told me he would mix up a weak solution of nutrients, and send it on over. (I'm a noob, he has more experience)

Two days ago I also started my 12\12 light schedule, and gave it some 300-500ppm nutrient solution in preparation for that change I was inducing. Now two days later, new growth declined slightly, however they all come out REALLY lime colored, almost pale yellow lime. I also gave it 2 cups worth of distilled water during this period as well

I just finished flushing the pail with DASANI water, and turned my lights back to 24 hours. (I hope 2 days at 12\12 isn't going to disturb them too much as far as the veg, flower cycle)

I am growing under the equivalent of a Procyon 100. I just built my own, using the same 3W LED's. And have had great result up until that change.

I hope there is someone who can help me out there. And I am open to any "Home brew" technique that would be as low cost as possible. Any advice as well is more than welcome.:rastasmoke:

NOTE:
I have no PH, PPM, or TEMP monitors inside my room. I cannot control those factors and that may be my downfall.... I get my stuff tested by my friend whenever possible. I recently however did add a temp prob, and can verify that the temp is no lower than 21C at night, and 26C during the day, from what I hear, that's perfect.

I've heard some stuff about using water that is coming from after a water softener. Where I live, the entire HOUSE is pipped in through the softener, so there is no point where I can get un-softened water. Should I be using my tap water, and just letting it sit out over night or something? I've been worried about it getting salt locked easily by using tap water.