Yellowing, going to brown ?

[dlipford370]

So this is happening to my plant. The plant was always showing a little bit of yellowing, then in the last 12 hours it turned to this. Now a little while later, another plant is showing brown tips on the leaves. They are 2 weeks old, and I have only given them distilled water, with just a drop of superthrive (mixed into my 2 gallon container). I know that some of my water had 2% daily value of calcium in them, but I don't think that would lock out my magnesium. Ph is good at 6.5, temps at 75, didn't have any way to get them air, but now I have some fans working for them. Any ideas? Thanks

[jzchillin]

what kind of soil are you using?

[dlipford370]

It's just super plain top soil, with nothin added to it. I mixed in about 30% vermiculite, but that's it. My other two guys are doing good in it, so I don't think that is the problem.

[jzchillin]

My first suggestion would be to check your PH. Phosphorus can be locked out when the PH is too low, and Boron can be locked out when the PH is too low and too high. That's what it looks like to me but I'm not an expert. Here's an excelent link with pictures to use as a future reference.
http://www.icmag.com/ic/showthread.php?t=11688

[SmknVTEC]

I think it is the soil. I used top soil once and it was not great. It is too compact and has weird drainage. Then you added more water holding properties with the vermiculite. Just because the others are doing well means nothing. Apparently this plant is the weakest link. It looks like boron but since they are only 2 weeks old that is impossible for any deficiencies unless pH is off or temp or something else.