Flower week 6 - Necrotic spots on upper fan leaves

I have tried to troubleshoot this myself and I am at a loss. I have a plant that I vegged for 4 months just to see what I could get off her. She was fine until a couple weeks ago when she started to develop necrotic spots on the top fan leaves.
I have been giving her 6.5 PH water and she is giving me a RO of 900. I am at a loss and am hoping you gurus can give me an idea at what I maybe facing.

1000W HPS
Average room temp is 75-78
Fox Farm OF soil
Fox Farm line of nutes

Give us pics with lights off, can't see shit like that. when talking about color.

Sorry wasn't thinking. I appreciate any advice you can give me.

Do you use a calcium supplement?

No, I don't. I have been worried to do so because where I live the water is extremely hard.

This is so common. I have experienced it and seen it across a variety of mediums, nutrient programs and strains.

I think it is most likely a calcium issue causing the most leaf damage. I dont think that its a simple issue of adding more calcium though. More likely, something in the environment is inhibiting the uptake of calcium. Could be too much of another element, improper environmental conditions like radiant heat stress or cold root zone temps.

I ended up just letting them finish. I tried calcium, magnesium, pH adjusting soil, flushing, more nutrients, less nutrients, etc. In the end nothing really reversed the damage but it did seem to max out. First some middle/older fan leaves started showing little brow rust spots. Then they got bigger and developed yellow around the spots. Then never leaves around the buds became affected. They started small and eventually almost consumed the leaf. The buds weren't affected, at least in terms of overall appearance.

If you can stand to have some ugly leaves on your pretty buds, I would just let them go. IME its not worth the effort and potential problems you might cause trying to fix it.

I had spots like that on my last outdoor Indica, and it was a K deficiency.
The leaves won't repair themselves, but the damage will stop progressing when you fix your def.View attachment 2644944

How long till the end of the bloom? Somtimes a normal die off could look like that, and if it is at the end I agree with MYOB and just let it go. Peace

not really sure on that strain because it is an unknown. Not a lot of trichomes on the bud leaves though and it is inherently a Sativa so they are around 5 feet. Saturday started week 6 so somewhere around 3-4 more weeks I guess it is hard to say with so little trichomes.

Neopimp said:

not really sure on that strain because it is an unknown. Not a lot of trichomes on the bud leaves though and it is inherently a Sativa so they are around 5 feet. Saturday started week 6 so somewhere around 3-4 more weeks I guess it is hard to say with so little trichomes.

Click to expand...

Good luck man, I have noticed my Sativas like more food than the Indicas, regardless in or out.
If I can help I will.

May have found the problem. Did a soil runoff and the PH on my pen was 5.9-6.0. Ran to the store and got a soil PH meter to verify the reading and it came up at 6.0. So thanks to Bakatare666's Chart it would apear that my Ca and Mg are locked out at that level. So my assumption is to not PH my water down until I can bring it up to 6.5. Does this sound about right?