Diagnosis?

[xxedgexx]

See attached photo.

If I had to guess, I know my temp is too high, with spikes into the 90's. I'm running CO2, but I'm only using a regulator and although most of the leaves look good and green, I don't really know what my PPM level is getting up to with CO2.

So heat stress wouldn't be surprising.

Outside of that, from what I've read and what I've seen in pictures, it might also be a magnesium deficiency. I'm using R/O water with only an A B solution. Should I add some CalMag?

Thanks

 

[leadplant]

I think you are correct that its a mag/cal def.
Those brown spots do look like the classic symptoms.
Dont use straight RO water - way too reactive with no buffering capacity. Whats the PPM of your tap? It may be better to use that. Or else add the CalMag to the RO water.
Temps into the 90's? - too high IMO bro although they say 90's can be OK if using CO2. What are the temps in the root zone? Thats what matters the most.

 

[xxedgexx]

That's the thing, out of the tap, my water is around 800 ppm. Temp at the root zone stays pretty much the same. I have two temp sensors, one mounted on the wall of the tent and one sitting at root zone. Temps stay the same.

thanks!

 

[cell]

Proper temps should range btw 75 - 85f. Above 85f has been known to stunt growth for many strains, but there a still a few indigenous equatorial strains which range w temps up to 125f, durable genetics.

 

[xxedgexx]

At the moment, I'm having a real hard time getting below 90. Not sure what to do. Is there any AC recommendations?

 

[Markus76]

75-85f?