I used the other picture based plant diagnosis faq, the one from drugs-something.com that gets posted a lot around here, and it matches the diagnosis that I see in the post you mentioned too, that looks like a calcium deficiency.

Browning tips, with little brown spots appearing in the leaves later in development. I've had browning tips a bit for a while and assumed it was because I used a soil with some nutes in it, but now I'm thinking the level of nutrients was quite low, as the plants seem to have perked up after their first feeding with big bloom and grow big this morning.

I don't expect the quality of the lower leaves that look affected to change, but hopefully it won't continue up the plant...

We'll see.
herbaltivo Reviewed by herbaltivo on . yellowing tips, brown spots, Ca deficiency? Hi, first time grower, 6 plants, bagseeds, day 23 of veg. 2 of the plants have nasty looking yellow tips on the lower leaves. Pictures say more than words. I water, but have not as of yet fertilized. I just got my fox farms products today and will be using them tomorrow. Soil is too wet to water today. 2 175w MH, 6 or so 100w cfl's for lighting. Temp is always around 78-80. Low humidity <20%. Was thinking about putting a pot of water in there to evaporate off some moisture. Three of Rating: 5