What's wrong here?

Any idea of what is going on with my friend's plant? Any specific advice is welcome. Thanks!

Is that a fungus?

No I don't think so. The fan leaves are yellowing and turning brown. They also seem a bit brittle. She is using Foxfarm Organic Ocean Forest Potting soil with GH Hardwater Floro Micro and GH Florobloom for nutrients. PH is kept at around 5-6. I suspect it is about 5 or 6 weeks (maybe more?) into the 12/12 cycle. She has a 450Watt HPS and the plant is about 12 inches below it. I thought maybe at first it was too close to the light but the fans keep it pretty cool.

pH is WAY too low, get it up to at least 6.5, and it looks like you have a calcium and /or Potassium deficiency or lockout... I am going to guess lockout caused by shit pH.

You say you're in soil, but what are those rock wool blocks I see? pH 5 would be for HYDRO... ???? Now I'm confused... your "friend" should post and explain herself... :D

potassium (potash) deficiency - (the last number in your ferts percentages) - you can use wood ashes and water, for fast fix, however, it's not really critical - (tends to be more cosmetic than anything) - your leaves yellow and die during later flower stages, the plant is dying, and throwing all its energy into flowering, for survival - and, as Stinky said, your pH is too acidic - :jointsmile:

My friend is my girlfriend. She doesn't have a camera or computer so I told her I would post this for her. Fixing the PH should be easy enough. The reason for the rockwool is that she has a couple of bubblers going too. Apparently the giant rockwool cubes make good plant stands cause they are way too big unless you are growing a tree. Is it too late for the plant in the picture or should she flush it with a 6.5 PH nutrient solution?

I,ve had a similar problem in the past, Get some canna mg additive (epsom salts). I'm pretty sure this will cure the problem. Good luck:jointsmile:

Aaargh it isn't an Mg deficiency. Listen to freewheelingfrank. He's got more experience than most of us.

seems like those plants are very close to being done, close enough not to feed them anymore, how many weeks in are they?? might be time to go

nevermind oppps haha just noticed the date this was posted