Sour Crack in hot soil

[Waira]

PK booster sounds good,...
...I don't see what you mean in the pics for Zn defc.? A little tip/edge color fade, which could be several things, too generic a symptom now to determine,...
..ditto for that lower, but usually when the margin teeth brown out at the tips, all along the sides, it's K related,....

 

[Sloth]

Yeah, they are very mild symptoms and you're probably right about being too early to diagnose. I've just seen this turn in to what I have believed to be a Zn Def a couple of grows now. Here's what these symptoms progressed to with Walter white:

My biobizz soil can tend to have a ph rise throughout the grow. Often 7+ph - perhaps due to not watering to runoff enough? This would explain zinc lockout, but I am making assumptions still.

I'm just doing a mini flush of 1x pot volume on each of the plants for the moment as I haven't watered to runoff once yet. Feeding ph 6.5 water the runoff was 7-7.5 ph

 

[Waira]

... what's you water source mate? If tap or well, what's the pH and TDS/EC? I need to know how hard the water is,... this cumulatively can start to drive pH up as the CaCO3 starts to build up, driving pH up with it,... Run-off is not a reliable measure of in-pot pH, and if you used anything but pure (RO/Di?very lowppm) water, unajusted, you will have that skewing results as well,... but it can offer a crude estimate, and that shows the in-pot pH is too alkaline, hence the defc.'s in micro's, Zn, Fe, Cu, B.... that plant looks like Cu defc. maybe Zn,... Flushing with 6.0pH water, low ppm, adjusted if needed will start to help bring it down,.... add in 1/4 strength nutes in the final pour,....

 

[Sloth]

My local tap water analysis is ph 7.42.
Magnesium 9mg/L
Calcium 91mg/L
Total hardness (CaCO3) - 264mg/L

So yeah, hard water with a lot of calcium - I think that's quite typical of the UK. Would you suggest that I use RO water in my grows? I had issues before when using RO water but in hindsight, it was probably my watering/feeding practices that were holding me back. Add the issues are mild, could I water to runoff every watering instead of flush?

 

[Sloth]

Had to bring down this beauty as she's throwing out nanna's all over. Gutted...she smells just like green crack too - was really hoping I would get a pheno like that. Ah well, the 3 that initially showed male parts are still in the tent getting checked over daily so still got 5 left. The 3 bears OG is looking like a hermie runt too - what awful luck haha. Mephisto suggested tiering all mix and light mix in their grow guide, so I'm really surprised by how much the plants hated it. Perhaps the new light is too powerful and caused them to take in more nutes?

 

[Dewey Matter]

Wow man, sorry to read about your problems with Sour Crack. From my experiences, they basically grow themselves. Good luck with the rest of the brood.

 

[Sloth]

Thanks mate, yeah it's not ideal... but here's to experimenting! At least I have learned a thing or two and still have 5/10 plants, so could be worse! Don't think I'll have the balls to run All mix with autos again though