Is this Heat stress?

[Attis]

I thought it was a nute def, possibly due to lockout. I now think it may be heat stress or even burning from the lights.
I have 5 bullriders and 1 OG Kush all in the same room. the bullriders didn't have any of the spots, however they did feel brittle. My only guess is that the OG is more sensitive to heat.

They are currently in the middle of week 4 of 12/12

And incase it helps, I am using

• GH nutes micro, grow, and bloom at full strength
• 400w hps
• feed schedule is 12pm, 6pm, 12am everyday for 30 minutes each then however long it takes to drain back into res
• lights are on from 12pm-12am
• RH is at 37%
• res temp is 71F
• room temp is normally 73F-76F except for the week up until I took these pics which it was spiking at 81F My guess is that it was between 1-3 pm somewhere since that is the hottest part of the day

Can anyone confirm or maybe point me in the right direction? I haven't seen any of the leaves getting worse and the flowers seem to be growing just fine, but I made a few changes to my grow room and since I did them at the same time, I can't tell what worked exactly.

FYI:

• I raised the height of the light to 24"
• I added an exhaust fan to help keep the temp below 78F It had gotton up to 80F-81F during the day. Not sure how long it stays that hot since I can't check them until the evenings
• I changed the nutes and h2o in the res and used RO water
• I also took the plants out of the flood trays and hydroton then rinsed the hydroton with my water hose incase the nutes were building up and causing lockout... this also helped me get rid of lots of lil pests that I could see floating in the water

That being said, I sprayed safer 3-in-1 a week before these shots were taken, and the pests were not eating the plants, just floating in the h2o so I am almost certain that this is not pest related.

I also have not had any further probs after making the said changes, I even see them getting better. I just need to know what the cause is so that I may be able to avoid it again.

Oh and I forgot to mention the the OG is about 5"-6" shorter than the Bullriders making it originally 24" away from the light. I was thinking that maybe the heat getting to 80F and the light combined caused this prob.

Thanks fellow farmers!

-A

 

[Zoolander]

Classic heat stress sign will be the leafs cuping up towards the light from the side of the leafs in

 

[samino]

Looks like a deficiency or nute burn too me!

 

[Attis]

Classic heat stress sign will be the leafs cuping up towards the light from the side of the leafs in

So then its not heat stress since it is only the tips?

Thanks, I guess it was the water then.

 

[Attis]

Looks like a deficiency or nute burn too me!

Can you tell me which type it may be and maybe a way to solve or even prevent?

Thanks!

 

[fuzzy]

Maby too much N.

 

[Caress of Steel]

What's your water and fertz like? I had rusty looking spots similar to those. Was a calcium def. Also had a mag def. I use GH Flora + Lucas with soft well water. No minerals = no calcium or magnesium which is usually found in harder well water. Bought a bottle of Cal-Mag and 4-5 days later plants look great.

 

[Attis]

What's your water and fertz like? I had rusty looking spots similar to those. Was a calcium def. Also had a mag def. I use GH Flora + Lucas with soft well water. No minerals = no calcium or magnesium which is usually found in harder well water. Bought a bottle of Cal-Mag and 4-5 days later plants look great.

I was using filtered water from the fridge then the fridge stopped working so I added 4 gallons of tap water but I dumped that water and refilled the res with RO water from a local water shop. I originally thought that it was a cal/mag def then I was thinking H2O now I am back to cal/mag def. So far nothing has gotten worse, which leads me to believe it was the tap water. I appreciate everyone helping out hopefully I don't run into any other probs from now until harvest.

 

[greenthumbdanny]

What's your water and fertz like? I had rusty looking spots similar to those. Was a calcium def. Also had a mag def. I use GH Flora + Lucas with soft well water. No minerals = no calcium or magnesium which is usually found in harder well water. Bought a bottle of Cal-Mag and 4-5 days later plants look great.

It really looks like a mag deficiency. Ive experienced many times when the leafs curl up and pray to the gods.
Cal-Mag cleared it right up. I always use it now. I have never had that again since using cal-mag for the past 3 years. GTD

 

[SENSI ZYM]

thats a clasic ph lock out bro flush with ph adjusted water and flush em and start feding again but with a lower dose , the burnt tips are overfert and the tips movei g up is the lockout also

 

[mace]

I tend to agree more with Sensi. Most likely PH lock out which can lead to the deficiencies you see. Do as he suggested and you'll be fine. Don't look to the leafs to heal themselves though, the damage is done.

 

[I B L]

:joint:the last pix you show with the jan o9 date stamp is def a :sick0018:cal mag issue:character0050:

 

[Core]

to miuch nutes.....

 

[Attis]

Thank you all for lending your help. I flushed then added the new water with less nutes and everything is great now. :cool0010:

 

[satty]

That was best thing to do. Go for a big flush and slowly
start over fresh, we hope that will do it.
:drink

 

[jansjukebox]

It's calcuim defeciency actually. Looks like it was caused by nut lockout from PH being off. Corect your PH and if you are growing in soil, flush it with double the amount of water as the size of pot it is in. The damage can't be corrected, but as long as the new growth looks good, you're on the right track. Don't go and try to just give it more Cal. you'll end up with another problem all together..you have to corect the problem and after you do just feeding it it's reg. food will just be fine. Good luck to you