Looks like Ca def and hot nutes, but not sure.

[GTC]

Problem: Yellow spots on leaves and some burnt/yellow tips Can't seem to figure out how to address the yellow spots on the leaves but the plants seem to be growing just fine. Burnt tips prolly nutes too hot, I lowered the EC already.

Medium/grow method: custom rdwc w/ constant water level in grow pots

Feed and supplements used: GH Flora in 2/1/3 mgb concentration and Botanicare CalMag+. 34% H2O2 added at 1ml/gal twice a week. Did full res change last weekend and ended up w/ ~900ppm(1.8ec). This seems too hot and it was holding steady for a few days but today the ppm went up to 1000 (still drinking plenty of water and ph drifting up) so I removed a gal and replaced w/ ph'd RO water.

water source: RO

PH in the root zone: 5.8-6.2 drift

Strain/age: 2x Fastbuds Strawberry Pie mid 8th week

light used: Mars ts1000

Climate:
Mars 2.3x2.3 tent
75-78F and 45-55%rh
64-68F res water temp
1 large airstone in each grow bucket with 18 lpm air pump
1 fan on floor, 1 fan above canopy, 1 small hepa filter on floor. All leaves rustle a bit

Additional info: No rootzone bac/algae problems, nice clean roots just slightly stained from nute dye. No pests/mold. Plants are also getting too tall and canopy is about 6-8" from light with no space left, so I'll be adding 2 full spectrum no-name LED light bars on the edges to get better light coverage (but this is another problem).

 

[Mañ'O'Green]

I think 900PPM is just too hot for autos. It looks like a calcium problem but most likely it is being locked out by too much nitrogen and/or Potassium.

 

[elcoloan]

And i think EC and pH rising means you should lower EC by at least 0.2EC / 100 ppm, and as MOG pointed out, the high EC might be causing antagonisms, might even be the CalMag what is causing the lockout... how much CalMag do you add?

 

[GTC]

And i think EC and pH rising means you should lower EC by at least 0.2EC / 100 ppm, and as MOG pointed out, the high EC might be causing antagonisms, might even be the CalMag what is causing the lockout... how much CalMag do you add?

I figured it's too hot so I lowered it by removing 1gal of nutes and adding 1gal of ph'd water. I did this twice, about 5hrs apart. Currently sitting at 5.7ph and 740ppm. Does Ca deficiency correct itself? or is it non-mobile?

The feed guide I'm following says to push to ~8-900ppm in flower but I guess I should stay at the same ppm I was at in early flower.

At first, I was using 2.5ml/gal (50% str) but had yellow spots. I then pushed to 3.75ml/gal once I went to preflower and the new leaves looked fine. Once in flower increasing overall ppm and seeing the same symptoms as above, I increased it to 100% str at 5ml/gal. Now I'm suspecting a lower ppm at 3.75ml/gal CalMag+ to be the sweet spot, which is what the solution should be at now.

 

[EP3]

Good luck with her.

 

[GTC]

Not much change today, seems to be getting a bit worse. Did another gaal of water replacement today for a total of 4 gals removed and replaced w/ ph'd RO water. I'm guessing it must've been nutes too hot since ph and ec are now going up rather fast overnight?

With increasing EC, does that mean my nutes are all out of whack now? Should I do a full change again or just keep adding water to dilute?

 

[elcoloan]

A friend who does DWC uses this chart and has had near perfect plants following it... it might help you while ohter chime in:

 

[GTC]

A friend who does DWC uses this chart and has had near perfect plants following it... it might help you while ohter chime in:
View attachment 1288884

Yep, I've been using that. Thanks. Hopefully the constant dillution will work.