imgrowing said:

every grow lately i've had 1 or 2 girls do this. at first i thought calcium but adding calmag did nothing. then i thought lockout because i feed full strength GH flora grow at 1150 ppm.
so after that i tried half strength and feed water water routine, but no change.
pro mix hp with ph'd feed, temps and humidity are premo, not over watering etc etc. several grows with exact same routine with no issues except lately.
all from seeds as there autos.
any idea why 2 or 3 out of 10 or so would do this?
just different seeds react different?

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Stokes said:

Looks like high ec causing ph swings. Whats your runoff

What is 1150 ppm, like 2.3 ec? Very few nutrient lines can be run that high where you’re at in flower

Also, if you let your substrate get that dry you will need considerable runoff every time you feed

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Mikedin said:

lights turned up too high, plant cant transpire, leaves burned up, easy fix back light up another 8" or turn down the dimmer the cal def and mag def are a side effect of lights too close

every strain can handle different intensities, run a tent full of clones and dial em in and itll never happen, on seed plants / first runs of a strain i stay 25% lower and increase 2-3% power per day till i see pull back on the leaves, back it down 5% and let em ride

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imgrowing said:

ppfd reads about 700 from tent buddy app, it probably isn't that accurate but this is what i always used before. watering every 2 days like i always have. GH flora series at full strength should provide enough cal and mag.
and i hear you about led's needing more cal-mag but very rarely ever use it.
at 24c and 50% rh vpd is at 1.03 so i'm in the sweet spot on that so the girls are breathing good.

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RoadKillSkunkHunt said:

I use GH flora series and I still have to use cal-mag. I don't use it in veg. I use it after about the 2nd week of 12/12. I'm not sure how much is naturally present in your water or what soil mix you're using so don't jump to conclusions just yet. However, it would be incorrect to assume that there is enough magnesium and calcium naturally present in the Flora series especially after your plants start calling for the large amount of calcium they do as they start flowering. It all depends on other things like your soil mix and your water source.

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imgrowing said:

looks like your growing photos while i'm growing autos, last time i checked my water was 35 ppm at 8.1 ph.
i feel, and i can surely be wrong, but in only 10-12 weeks autos finish fast enough without added cal-mag.
at least so far anyways except for a couple girls here and there.
that's also 1 reason i don't flush promix hp, i don't feel they have enough time to build up excess salts.
again, i could be wrong and the grows probably could get better.
thanks again

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RoadKillSkunkHunt said:

I do grow photos almost exclusively but I have grown a few autos here and there.

Promix HP doesn't have nutrients of its own. It comes with a good dose of beneficial microbes but no nutrient load. 35 ppm is quite low actually. There's not much in that water at all. I get what you're trying to say about the calcium but I think its actually the source of your troubles.

Promix HP - zero nutrient load.
Water - almost zero ppm. Even autos need that calcium at the start of flower.

I do agree that you don't need to flush your promix though.

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imgrowing said:

next run i'll use cal-mag 2 weeks into flower and see how that goes. 2ml/gal or 5ml/gal ?
what would you suggest, never hurts to try, at least for me as i've done 2 seed runs and have a couple thousand seeds

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