Hi all, so as a new grower I could use some help again. I have noticed the other day that I’m losing all the colour in my leave. It’s happening to 2 different strains in 2 different rooms and one is 3 weeks into bloom and the others are 5 weeks veg. Ph water to 6.4-6.5, led lights, AN SENSI GROW AND CONNOISSEUR line nutes, pro mix hp, temp 77, humidity 45. Everything was great up to 1 week ago.!
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Can you post a pic of the whole plant? Looks like magnesium deficiency, though. Are you using reverse osmosis or otherwise low ppm water? You may need to add some cal/mag supplement.
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I’m using tap water and have been adding cal mag from day 7 of veg
How much per gallon? You might need to bump it up some, or maybe just add some epsom salt (5ml/gal) in your next watering. Or it might not be magnesium lol
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Trying to switch my head to metric, but it’s just not happening…
It really looks like a magnesium deficiency to me, but that could also be a pH issue if you’re feeding plenty. I’m not super familiar with pro mix, haven’t ever used it myself, but I think it likes a little closer to hydro numbers for pH, doesn’t it? Maybe you’re locked out on magnesium because of the pH. Lemme think who else uses pro mix and maybe someone else will chime in, in the meantime. @BIGE @Donaldj
Thanks for the help.35ml I believe
That’s per liter, so right at 1.4 per gallon…that’s only about a 1/4 teaspoon per gallon, which sounds low. But I’m not familiar with that line, could be dead on. I’m leaning toward the pH. I’m doing some searching.
35 ml to 5 gallons
So 7ml/gal. Anyway, everything I’m reading is saying that cannabis does best at a slightly lower pH than soil in promix hp. Maybe do both, one at a time. Next water, try swinging the pH down some…maybe shoot for around 6.3. Do you test your runoff? Do you test TDS of the runoff?
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I usually do but ran out of time last watering. I will check my runoff next watering and bump cal mag
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If the TDS of the runoff is where it should be, hold off on increasing feeding until your pH is in proper range. If it’s not, the nutrients can’t be taken in by the roots anyway.
I also understand that pro mix requires slightly lower ph. Runoff numbers will help as well as ppms.
Some of the leave look like potassium deficiency, but it could also be nute burn/mag deficiency.
Couldn’t sleep so I flushed the plant in the picture. Put 3 gallons of tap water @ a ph of 7.02 and tds @ 257. Runoff is now 5.72ph and 845 tds
Im using promix hp & ph between 5.8- 6.0. Up till start of flower i was phing @ 6.3 but was having calmag issues until i dropped my ph to more of a soiless grow. This is my first attempt with promix hp before ive obly grown in soil.
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Promix likes lower pH, I’m using Promix and targeting 5.5-6.2. They have a good video on their website explaining what pH to target.
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I keep this in a text file and always find it handy:
.5mL/L = 2mL/Gal
1mL/L = 4mL/Gal
1.5mL/L = 6mL/Gal
2mL/L = 8mL/Gal
3mL/L = 11mL/Gal
4mL/L = 15mL/Gal
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This is all great information. I’m going to flush a different plant today at a much lower ph and see the side by side
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Thanks @TommyBahama, I’m all out of likes! 