# This always happens late in flower



## Lesso

I always seem to get cal or mag deficiencies late in flower. This time it started at 49 days. This has happened when i have used gh 3 part or floranova 1 part. I typically run 1500 to 1200 ppm in ro water during flower. My ph will fluctuate between 5.6 to 6.2. I dont know how to treat other than flush the plants and dump my res. It didnt work this time however. Is there a way to prevent this in the future. Should i ramp up the cal mag around week 7? Im certain its hurting my yields. The perfectionist in me is irked to say the least. 

View attachment 20170206_101928.jpg


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## Budlight

I was having the exact same problem not sure if I have figured it out yet or not  wish I had more advice for you there's lots of  smart people on here though somebody should be able to identify it


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## RubyRed

I start Cal/Mag in week 2 flower.  why wait till its too late?. Did you not see signs a couple weeks ago?

tcabs


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## Lesso

I hope some one can.  It isnt all that distressing but it is frustrating.


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## Kraven

Lesso it looks like your Ph is getting off, more than likely due to salt build up in the medium. When you see this with or without tip burn you need to flush the medium to clear the salts because the pH in the root zone is off. Also try cutting your bloom nutes by 20% next run, as long as they don't look hungry keep it that way....that will help with salt build up. Or do a mid flower flush as you begin to take the N away and replace it with P and K for the final bulk, that way the medium wont have excess N left over and not being used. I hope this was helpful. Peace

Edit: In error I never asked what medium your using....if hydro it's the same issue, just easier to handle and it corrects very quickly.


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## Rosebud

Some folks start the cal mag much earlier,  do you think that is it?


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## SHOT

Curious to know what is the problem... it could happen with anyone of us!


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## umbra

the GH 3 part has cal/mag so if you see it late in flower, it is mostly a ph problem and nute lockout rather than a lack of it.


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## bombbudpuffa

I'm going with pH issue too. I have one plant with similar leaves and it's from something I gave the plant(chem bloom booster in an all organic grow).


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## Lesso

All good info. thanks all. Kraven, I am in hydro i will flush again, re fill my resivior, and run lower ppms. Umbra i think its more ph too. Bombbp, i am using bud candy but i have been since week 2.


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## SHOT

Goodluck lesso


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## bombbudpuffa

Lesso said:


> All good info. thanks all. Kraven, I am in hydro i will flush again, re fill my resivior, and run lower ppms. Umbra i think its more ph too. Bombbp, i am using bud candy but i have been since week 2.



All I meant is my booster threw my pH off and my plant looks like yours. Didn't mean to imply you were giving yours something that was throwing yours off though I do believe you have a pH related problem. Sorry I wasn't more clear.


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## Kraven

It's pH..... more than likely he had a rapid change inside the recommended range of 5.7-6.2. I'm not saying his pH is outa whack, but a rapid change will do this every time. I run a 55 gal rez with a 45 gal ATO so as the res needs water the ATO [automatic top off] keeps the rez at the right volume....that also makes me have a positive ramp from 5.7 - 6.2 over 7-10 days, at 10 days I don't change the rez and drop the pH back to 5.7. I do an add back of 20% of all the nutes which drops my pH again to around 6.0....and bumps my ppm up about 200....not a huge change and I will let that run until the pH hits 6.2 or the ppm's drop below 800. Then a rez change but I run it from 5.9 -6.3 for the rest of flower using the above method. My average flowering ppms run around 1200. Hope this is helpful lesso, you girls look great, they are just doing the pH bow for a minute.


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## zem

Lesso! I have had this, it is caused by many factors that stress the plant in late flowering, and plants at that stage are easy to show stress. Last time I tried I had 4 res's trying to combat this issue and it turned out that the plants were much happier with higher ec  as i progressed, so that I would get to week 5-6 close to 2000ppm. Another factor is the sudden fluctuation in ph and/or fert concentrations. all other factors like temps and humidity have more effect on the plant in flowering, and there is the factor of salt build up and what else. What I am saying is that it is somewhat normal to have some issues in later flowering, it is like you are trying to keep the plant alive when it is trying to die. I use the following guidelines only for reference: week1 1200ppm, week 2 1400, W3 1600, W4 1800, W5 2000 maintain it there until ripening then i decrease gradually until harvest for 1 week. This is very dependent on strain and fert type, but I have found that doing so helped a lot in forming more bud


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## The Hemp Goddess

I always add Cal-Mag during flowering when using GH 3 part.


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## Lesso

Kraven said:


> It's pH..... more than likely he had a rapid change inside the recommended range of 5.7-6.2. I'm not saying his pH is outa whack, but a rapid change will do this every time. I run a 55 gal rez with a 45 gal ATO so as the res needs water the ATO [automatic top off] keeps the rez at the right volume....that also makes me have a positive ramp from 5.7 - 6.2 over 7-10 days, at 10 days I don't change the rez and drop the pH back to 5.7. I do an add back of 20% of all the nutes which drops my pH again to around 6.0....and bumps my ppm up about 200....not a huge change and I will let that run until the pH hits 6.2 or the ppm's drop below 800. Then a rez change but I run it from 5.9 -6.3 for the rest of flower using the above method. My average flowering ppms run around 1200. Hope this is helpful lesso, you girls look great, they are just doing the pH bow for a minute.


Great info. I did have a rapid swing of the ph. Spot on


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## Lesso

zem said:


> Lesso! I have had this, it is caused by many factors that stress the plant in late flowering, and plants at that stage are easy to show stress. Last time I tried I had 4 res's trying to combat this issue and it turned out that the plants were much happier with higher ec  as i progressed, so that I would get to week 5-6 close to 2000ppm. Another factor is the sudden fluctuation in ph and/or fert concentrations. all other factors like temps and humidity have more effect on the plant in flowering, and there is the factor of salt build up and what else. What I am saying is that it is somewhat normal to have some issues in later flowering, it is like you are trying to keep the plant alive when it is trying to die. I use the following guidelines only for reference: week1 1200ppm, week 2 1400, W3 1600, W4 1800, W5 2000 maintain it there until ripening then i decrease gradually until harvest for 1 week. This is very dependent on strain and fert type, but I have found that doing so helped a lot in forming more bud


Great advice. Do you run co2? My tips started burning on this strain at 1550 ppm. I backed it down a bit and got a sudden spike when i mis-measured the nutes. Also swung the ph like crazy.


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## Lesso

The Hemp Goddess said:


> I always add Cal-Mag during flowering when using GH 3 part.



I think you have said that you use ro water.....how much cal mag and when i.e. week 1 through 6 etc?


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## zem

Lesso said:


> Great advice. Do you run co2? My tips started burning on this strain at 1550 ppm. I backed it down a bit and got a sudden spike when i mis-measured the nutes. Also swung the ph like crazy.



No co2, some strains cannot take high ec and the type of ferts is basic. Too much N in any fert will cause many problems, I use fertilisers from raw chemicals and mix myself giving me more flexibility. It is also very good to increase ppm gradually I was adding it like daily, doing a lot of daily analysis trying to figure out what is missing and trying different things in different res's, also the phosphate ion is very tricky to maintain and i found calcium to be way way overrated as a problem especially with tap water.


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## Lesso

Zem....do you find as i do that most problems in hydro stem from ph?


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## zem

Lesso said:


> Zem....do you find as i do that most problems in hydro stem from ph?



yes and no, PH is indeed easy to mess up if you do not give it enough importance, I find it basic to not let it fluctuate suddenly and make the drifts smooth. That done, there are other factors, I have found that a sudden change in type of fertilisers had a drastic negative effect even though I had PH and EC the stable, so yes, ph is the most challenging because it needs constant maintenance, but other factors are also very important...That is my experience up till now


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## Kraven

I watch pH way more than EC / ppm. The plants will tell me if the mix is too hot just by the way the numbers move....pH has to remain stable and on a gentle rise. After you tweak and get dialed in the numbers are very consistent from grow to grow. Peace


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## Lesso

For the sake of anyone wondering.  The flush and re freshing my nute tank seems to have stalled the necrotic spots. Before i dumped my res i had a ph of 5.4...too low. I figured out the finisher that i was using dumped my ph by .5 at the recommended volume. I have countered this by using silica blast bringing the ph back up to 6.0. Ss1 was always the most sensitive to ph which makes sense as to why it showed earlier and has the worst damage. I havent seen any more spots on the leaves. Also my ppms were way too high....brought them down to 1200 yesterday and today they are looking fresh and reaching for the light.


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## zem

yeah changing the res many times solves it. i dont let ph above 5.8 at that stage, usually 5.5-5.6 but with much higher ppm. good luck


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## Kraven

That would be it lesso....btw I use SB in place of pH up myself...since I'm in R/O its a bit helpful and I use far less to get my pH to move.


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## Lesso

Thanks guys. That is why i come to this forum and i am glad to be in this community. Growers helping growers.


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## 400watter

Good to see things bank on track Lesso. I flushed my cssh yesterday and she is looking happy now. Back to nutrients tomorrow but at a lower ec reading.


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## Hushpuppy

In Hydro/non-organic, the plants live and die with pH. It is as important as light. That is because in non-organic, the plants feed according to the pH. In organics, the microbes feed the plants. pH is always in a state of slow change. That is because the different elements in the solution and/or medium are constantly changing in amounts and concentrations with each other as the plants remove elements and water from the solution. This constant change causes the pH to change. If the reservoir is big enough then the pH will change much slower. Low ec/tds can also cause the same issues as there isn't a strong enough solution to keep pH from swinging wildly as elements are removed by the plants.


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## Lesso

Very true hush. My res is 45 gallons but when running at high ppms the ph swings much more.


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## Gooch

also choose your silica carefully, if its potassium sillicate then you are also adding in extra potassium and that is what adjusted your ph, silica should not affect ppm, or ph if its pure. the best silica i have found is the raw silica


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## Hushpuppy

That's odd that your pH swings much more at high ppms. It will always swing and may swing farther with higher ppms but it should move slower unless your plants are large and are really sucking down the solution. The silica thing could be the culprit. A friend of mine tried the silica and had fits trying to control the pH of his stuff. He finally had to quit using it as he couldn't keep it under control.


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## Gooch

check out the raw silica, its silicone dioxide derived from diatomite doesnt affect ph, or ppm


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## Hushpuppy

What exactly does the silica provide for the plants, I used to know but can't remember :doh:


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## Gooch

provides it flexibility in the stems, and it also is used at the point of infection to isolate it and stop it from spreading. its part of the natural immune system


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## Hushpuppy

cool thanks


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## Gooch

here is an excellent video on biostimulants


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## FemFlopPollenDrops

what are your environmental factors and what is your ph when feeding because this has ph written all over it.


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## BigJer

Kraven said:


> That would be it lesso....btw I use SB in place of pH up myself...since I'm in R/O its a bit helpful and I use far less to get my pH to move.


Crushed coral, crushed sea shells and beach sand can do the same thing and much more safer than the blasting silica


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