Everything has been fine since i put then into flower 3 weeks ago. I tried feeding calmag. I tried less nutes and nothing is changing.
I feed them their nutes then 3 days give them the rest as they only eat half a bucket between them. Ph is 5.8-6.2, temp is 22-28°c humidity 45-55%. Their in 8.5L pots. Theyve gone from being absolutely beautiful to yellow and sad and un healthy
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I would get the pH up. The sweet spot is 6.5 for a soil grow.
What is your runoff PPM and what nutrient product(s) are you using?
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What kind of “soil” also 
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Unsure of ppm as i dont have a ppm reader. My nutrients reccomend 5.8-6.2. Im using garden of eden its a nz brand really good brand and im using canna terra professional soil
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It is a coco pH, not a soil pH. Can’t offer much help without understanding PPM. I expect your PPM is low.
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Nah its soil ph brother
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Soil ppm low mean what exactly?
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They just look hungry to me…
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Hungry as in?. They get fed just under reccomend dose twice a week
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I has a similar issue once it turned out I was actually giving my plants too much (intensity wise not duration wise)light and the yellowing was essentially “sunburn” for plants so to speak
Maybe turn it down a bit and see if it stops spreading
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He’s right. Here’s their chart:
Nonetheless, I expect the experts here will suggest increasing the pH of your water and water + nutrients to 6.5. That alone might solve your problem.
If you want to speed things up, you can give it pH 6.5 water, measure the runoff pH, and repeat until the runoff measures 6.5 – all in one go.
But they aren’t absorbing the nutrients well because your pH is too low. You must suspect this or you wouldn’t have mentioned “lock out” in your title.
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Noted on the ph. Nah bro i dont even know what causes lockout. I just got advised it could be lock out which is why i put it
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Nutrient lockout results from the soil’s pH being too high or low. That makes it difficult for the plant to absorb nutrients, no matter how much may be surrounding the roots. The pH range that’s recommended usually for pot growing in soil is 6 - 7. I split the difference.
As for ppm, this ILGM guide is worth reading.
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Exactly… low ppm means they aren’t getting enough nutrients.
It looks like N deficiency. It’s starting at the bottom and has worked it’s way up. There are no tell-tale brown spot/patches that are associated with low ph.
Sweet spot for N is 6.0 - 8.0
If you look at what ph problem looks like, it looks more like this:
I don’t care what the nutrient line ‘says’… they have you cut back on N after week 2 of flowering and plants need N all the way till the end… not nearly as much, but they do still need it.
This is not the only reason for lockout… the MAIN reason is salt build up at the roots. I would recommend a flush to rid the soil of salt build up, but you HAVE to follow that up with more nutrients (or the lack of nutrient uptake will look much worse at first) at about half strength, then go back to normal feeding.
Take this info for whatever you want. NO nutrient line is 100% self sufficient. The plants tell you what they need and they are telling you it’s hungry (for whatever reason…)
You should invest in a ph/ppm pen. I used them for quite some time but now I listen to the plant and only use the pen if I can’t figure out what they are saying.
If PPM is in-line, but PPM out is high… you have salt buildup. and they are not absorbing it.
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Agreed.
Then there is the Plant Law “Law of the Minimums”
LSS “No quantity of supplied nutrients will assist growing, if minimum required nutrients are not supplied in form obtainable/available to the plant”.
Some version of those words, USU Soils class, 1974.
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Aha. I suspected there might be more to the diagnosis than pH, but didn’t think it would turn out to be irrelevant. It’s good we have experienced people like Caligurl, who can diagnose based on the plant’s appearance, rather than having to rely on measurements.
The procedure I described, involving watering until the runoff measures correctly, should help solve your problem, but you’ll be looking for a ppm target rather than pH.
The ppm pen one of our other experts (Lostgirl) recommends is this one (5 in 1 version). The same one is also available here at a much lower price if you don’t mind ordering things directly from China.
@Caligurl: Thanks for continuing my education. Is one of your photos a “pH too high” and the other a “too low?”
Also, there’s a question waiting for you at the bottom of this thread.
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So do i just feed more N or do i flush it amd then feed nutes??. Ive been told its N deficiency but i dont understand.how this could be theyve been fed perfectly
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Caligurl’s diagnosis is nutrient lockout, caused by a buildup of salts at the roots. She recommended a flush because, until they’re washed away, the nitrogen can’t be absorbed.
The procedure I described will get your pH right and wash away at least some of the salts. Until you have a way to measure ppm, the only way to know if the flush is adequate is to watch the plant.
Caligurl recommended giving half-strength nutrients after the flush.
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Doesn’t matter if you fed them ‘perfectly’ if you have salt buildup at the roots. when using salt-based nutrients, you need to water to about 20% runoff each and every time you feed to keep the salts from building up.
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What i mean by that is idk how their could be a build up. Up until flower they were fed silica calmag and nutes 1 time over 7 days then water once or twice depending 1 week before flower i stopped solica and calmag and they dont often get a full dose of nutes. Therefore their wouldnt be enough nutes to cause a build up?. So when your saying to flush. Use 6.5 water give them a good flush then wait 2 3 days and give them half strength nutes? Maybe with some N rich supplement
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