Whats with my babies?

It's my first grow and we're a few weeks into this thing (germ was on 4/13/09). So far so good, until this morning when I went to check on my babies.

There's some yellow tips, and small burn spots. I'm thinking Magnesium deficiency is the most likely culprit. Take a look at the pics and let me know if you agree.

There's three Belladonna and three LA Woman seedlings. Summer tent is 2'x2'x5'7". The temp has been pretty much stayed between 70-80 degrees depending on whether its day or night. There are four 2' T-5 bulbs overhead kept as close as the humidity dome will allow. (Still using the dome, however I can't seem to keep the humidity any higher than 36% or so.) Right now they're potted in 4" pots with Roots Organics soil by Aurora. They're being fed with Foxfarm Nutes. They were getting 2Tbsp/gal of Big Bloom. I watered last night, but after I noticed the problem, I topped them off with the new mix of 2Tbsp/gal of Big Bloom and 1tsp/gal of Grow Big.

I think I got a tad behind on upping the nutes. The Grow Big, has Magnesium as well as a bunch of other minerals the Big Bloom doesn't have. I'm hoping they just started getting hungry and will perk up within a few days.

Heres the pics of what's going on...

Any help would be greatly appreciated. I've searched the threads and like I said I'm pretty sure they're just nute deficiant since I probably should have had the Grow Big on them well over a week ago. All I've read is how new growers over do it, so I've been trying to take things slow. I just hope I can correct this before things really take a turn for the worst.

look in the plant problems section you should find ur answer there im a bit new to this so i cant rele help ya

That's how I came to the possibility of magnesium deficiency. Its hard to tell though because the condition of the plants in those threads were so much worse than mine.

Indoor growth cycle, light time and lumen per square foot for dummy's:

This is information Iv gathered in my research to grow in a easy to read format for quick refrence

The process of germination: They Requires no light and is usually completed in 3 to 10 days.

For plants in seedling and clone: This stage require about 400-500 lumen per square foot 18 to 20 hrs a day. This seedling stage is completed within four to six weeks.

In vegetative growth: At this stage they require about 2,500 lumen per square foot but the more light the better for 18 hrs a day and The vegetative stage is usually completed in the third to fifth months of growth.

In flowering stage: They require about 10,000 lumen per square foot for 12 hrs a day and absolute darkness for 12. Flowering generally lasts from 45 to 90 days indoors.

Lighting Efficiency Comparison
Just as an automobile's fuel efficiency is measured in miles per gallon, light bulb efficiency is measured in terms of lumen per watt—the amount of light produced for each watt of electricity consumed. More lumen per watt means more light for your money.

The T-5 is a Sunleaves Pioneer Jr IV. It gives out 7200 lumins. So unless you're telling me that I'm killing my plants with light, I'm not sure I understand the purpose of your post.

No one has any ideas?

I've been trying to slowly top it off when I can with the new solution. As of this morning there is not much change.