Help With Leaf Diagnosis

[Dinkus]

Hey guys, been around for a long time but this is my first time taking the plunge. I would love some advice on what is happening to my lovely ladies. I am noticing two separate issues.

A little info first:
I am running two strains, Diamond OG & Mendo Grape Kush

I am in week 2 of Bloom

I am using rockwool cubes and rockwool fill in greentree buckets with ebb and flow, currently flooding the buckets once every 3 days.

I am running House and Gardens Aquaflakes schedule for 6 week veg and 8 week bloom using the calculator on their website

Ok if you need any more info please feel free to ask.

Issue number #1 after doing some reading here, I believe to be Nutrient Burn but would appreciate some confirmation. It is really affecting the Mendo a lot more than the Diamond. The Diamond showed no signs at all in Veg but now is starting to show a little on the tips but still nothing like the Mendo which was showing signs in Veg and now in Bloom it seems worse.


Issue Number 2 is proving to be harder to identify, It is only affecting the Mendo and not the Diamond at all even though I am feeding them the same food. It seems to only affect some leaves but not all, old leaves and new leaves alike. It presents as small rust looking spots and spreads very slowly until it covers the whole leaf. In veg I only noticed a very small amount of leaves with this condition but now in bloom it seems to be affecting more leaves.



Overall everything seems very healthy and happy but I would like to solve this issue so it does not affect the end results.

Thanks for looking and I appreciate any and all input.

 

[Dinkus]

Did a little more reading and I don't really see how it could be locked out of Calcium but it does look similar to the pics I saw.

Could it be Potassium or Phosphorous perhaps?

Also if it is a nutrient deficiency, why is it only affecting one strain?

Is it possible that one strain wants more of a specific nute than the other strain so what is fine for one is deficient for the other?

 

[Dinkus]

I'm really leaning toward Potassium Deficiency at this point from letting my ph drift towards 6.0-6.1, what do you guys think? Is there any reason I should think otherwise?

So I am planning to do another flush for the nute burn, back off the nutes a little and drop the ph more towards 5.7 then 5.9. Sound reasonable?

 

[tempes~tos]

Check for fungus gnats or root aphids. Spots like that on the leaves can be caused by unhealthy roots, caused by a fungus introduced by fungus gnats, or from root damage caused by root aphids.
It could also be lockout but I doubt you would have lockout like that from only 6.1 ph.. thats not too far off. Wouldn't hurt to take the action you mentioned on the feed also and see if you notice an improvement.

 

[Speed of green]

high e.c feeding can cause lockout, do you know what strength you are feeding at?

Also if you are letting the Rockwool get too dry that can cause lockout.

lowering the feed strength and bringing the ph down is a good start, also dont expect the leaves to green back up after the issue is fixed. Youre looking for it to not get any worse.

 

[Dinkus]

Thanks for the replies guys, I did see some fungus gnats during veg. I bombed everything when I moved them to bloom. I haven't seen any since then but I can't check the bottoms of the cubes anymore since they are in buckets now. Is it weird that the spots are only on one strain though?

I have been feeding them around 1.8-2.2 EC so nothing crazy. I am really nervous about over watering so I may let them get on the drier side, but nothing ever wilts/droops or anything at all.

Is there anything else I can do at this point? I am in week 3 of flowering now and they look good but I still don't like the spotted leaves.

Can I cure the fungus if that's what they have?

 

[Speed of green]

1.8-2.2 is high enough to lockout if the pot is drying out. I think you are on the right track.

Wilting means you are too late, if you ever look closely at healthy roots you will notice they are a little fuzzy? the fuzzy part is millions of tiny roots, this part is what really absorbs nutrient solution. These little fuzzies are the very first part to die when the roots dry out, and the plant wont even be wilted yet.

you can check your runoff ph and ec. if the pot has been drying out then there will be an excess salt buildup.