Leaftip curl, dark patches, rust spots; affected areas are crisp - a pH problem?

Fan leaves throughout a couple of my plants are going necrotic. Typically the very end of the leaf starts to curl and it continues and doubles back on itself. The curling areas turns dark grey and becomes very crisp. This occurs not just at the leaf tips but in the midriffs of leaves, prompting the leaf's shape and structure to deform, turning at odd angles (always upwards and towards the stem), accelerating the folding-over process. There are also the odd rust spots found dotted around affected leaves - these can be seen from under the canopy when light is shining through them and are easy to identify.




I'm growing Utopia Haze organically. I have five plants 40 days through flowering (about half-way, slow Hazes...). My own brief diagnosis: low pH has locked out Calcium, Magnesium and Phosphorous. The dark blotches might indicate lack of Phosphorous, the rusted dots and leaf curl lack of Calcium and Magnesium, even Potassium. Obviously I would love to hear what others think about the situation. I am growing in BioBizz Light-Mix, and using BioBizz Grow, Bloom, Top Max formulas and Canna trace elements. BioBizz's grow chart recommends 4/4/4 (ml) per litre at this stage of the grow. I have used a couple full strength doses lately but have been diluting on the whole.

Here is a full run down of my pH measurements:
- Tap Water: 8.1
- Filter Tap Water (via a Brita filter jug): 5.9
- Bottle Highland Spring water (as a test normal - the meter was calibrated with included 7.0 solution): 7-7.1
- Nutrient solution (4/4/4 mls per litre) using filtered tap water: 5.5
- Nutrient solution with tap water: 5.6

Having only acquired a liquid digital meter the day before yesterday, I have identified that I have essentially been pouring acid into my medium (pH 5.5) for the past month plus, locking out the above elements and probably more. Yesterday I performed a full flush of all five pots with shower water (identical pH to tap water even at warmer temperatures).

The (startling) results:
- First stage flush from the immediate run-off: 6.5
- Run-off from the ultimate (cleaned) flush: 7.1

This left me somewhat confused. Sure, I realise that measuring pH from run-off is not accurate as you are diluting any acidity or alkalinity with a base solution of about 8 (unfiltered tap water) in my case. But real soil conditions must have been far more acidic (towards the 5.5 of the unbalanced nutrient solution), at least this is what my hypothesis would like to hear!


Unfortunately, no one sells dolomite lime in my area and I was forced to buy synthetic pH up (potassium hydroxide). Post-flush I added a light dose of balanced nutrients (pH 6.5). Literally, two drops of the (50%, not sure about molarity) potassium hydroxide raised pH of a litre of nutrient solution by a whole point! I am letting the medium dry out until at least tomorrow, most likely Monday before adding anything further. The soil is still drenched. I will add a very light mix of nutrients and trace elements with a raised pH courtesy of the potassium hydroxide.

Couple questions:
- recommended course of action? I am thinking of adding a solution of pH 6.8 next time rather than 6.5 to make sure there is proper uptake of Calcium, Magnesium and Phosphorous.
- the filtered tap water, ditch it? Is it fucking with salinity (much lower pH than regular tap water)?
- initially the symptoms occurred lower down the plants but fan leaves towards the very top of the bud stacks are firstly showing the dotted rust spots then turning over and doing the blackened-necrotic crisp-flip. Is this purely indicative of lockout of mobile elements?
- how much can high temperatures exacerbate problems; temperatures range from 25-8 degrees Celcius in my setup?

Hm well the tap water Ph where i live is like 6.5! but yeah i had this problem mate, ph was on 5.0! and i didnt even notice so i mixed my nutes with some water then used ph up on it waited half an hour and my ph was on 6.8 - 6.9 . ph is so important its a shame alot of people look past it . But yeah good luck mate hope your grow goes well ans you get alot of tasty bud!

i was getting all that stuff until adding lime to my soil, ph is now buffered at around 6.9 and the plant seems to be doing better than the other ones without lime. i can take picks of the side by side so you can see difference. if you want. its only on my current grow i used it on one plant and i can tell you ill be mixing it into all my soil in future. a lot of people dont like to use lime but i dont know why because it worked for me. the other plants without lime i have now added a teaspoon to the top soil (2 days ago) but its too early to tell whether it will make a difference.
hope you get it sorted anyway.
lu

is that 25 - 8 temps, that can cause stunted growth and with the wet soil will also lock out nutrients, get your self a heat mat if you can to keep the soil a bit warm in colder conditions. i know its not easy for a lot of people to heat a room all night so i aint gonna advise that. also one thing i have learned is dont flush as soon as you see a problem as it can cause more probs than its worth. everyone nowadys says flush flush before thinking what effects it could have on the plant, flushing does not fix every problem.
i am only a bit of a noob but this is stuff i ahve learned from experience and things are getting better for me now. ive only ever asked about 5 questions on this forum and only one was answered so i must say research of your own is better than getting differing opinions from lots of different people. try and get some lime and keep the soil heated if you can, even garden lime will do as its the same stuff. you must be able to get that at a garden centre.
lu

Hi, thanks for the replies people!
Lucifer - I didn't flush straight away - I've noticed symptoms for a couple of weeks and they have finally come to a head with leaves on one my babies turning all over the place
I would get lime but as I mentioned I can't get it locally, next grow will definitely have this addition.
"research of your own is better than getting differing opinions from lots of different people" - couldn't agree more! I've done extensive searches of this forum with loads of different search terms, there are two or three threads with similar problems to mine. Of course, it's the peculiarities of each and every one of our setups (unique) that make diagnosis so difficult. What we can discern are trends or patterns which help identify problems.
Also, heating the soil is too impractical, but thanks for the suggestion. 25-8 is the ambient air temperature range. Feel free to add pictures if you think they might be helpful, I appreciate any input either way.
Cheers again, check out my other thread detailing my grow with regular updates.

what ph was the water when you flushed? before and after?

you seem to have your head well screwed on and im sure youll be on top of your problems very soon, also your right as everyones grow is different and when you ask questions you do get a lot of diffrent answers because they base info on how they are growing. very difficult sometimes to siagnose problems.
i will keep up with your grow and hope you have great success.
lu

IVIars said:

what ph was the water when you flushed? before and after?

Click to expand...

"The (startling) results:
- First stage flush from the immediate run-off: 6.5
- Run-off from the ultimate (cleaned) flush: 7.1"

The base pH of the flushing water was 8-8.1


Thanks lucifer
Are you growing right now?

Crisping has accelerated today but it will take a few days to see positive effects from introduction of nutrients and water with balanced pH. Worries me when I see the top most fan leaves freckling with rust spots, I know they will curl and die most probably... sigh.


p.s. Oh by the way - found out that Brita filters take out not just the heavy metals like lead and copper but "limescale." That explains the acid drop-off when using filtered water. I am seriously considering using bottled water for the last month of flowering.

so you put in water at ph 8, water came out at first ph 6.5. Split the difference your soil was probably a ph of 5. Its a rough way to figure out the ph of your medium but not 100% accurate. Final ph was 7.1, water going in was 8, so roughly the ph is 6.2 in your soil, roughly. Try running through water ph @ 6.9-7. youll have to use more gallons, but itll help stabilize the ph to a range where you want it. You can also add dolomite lime (garden variety) top dress as long as your not to close to harvest

also because you are flushing just make sure your holes are nice and enlarged in the bottom of the pot and if you can raise the plant a bit up off the floor. this will all help in getting the excess water out of your medium quicker. yes i have a few on the go at the minute, skunk 11, white berry and the full magus genetics range. the white berry and skunk are great grows!
later
lu

Hi again and thanks for the ideas, all taken onboard and appreciated.

Vlars, you are subtracting the difference between the tap water and run-off values from the tap water value to get those estimates, correct? Good tip, cheers.

I'm aiming for the upper half of 6.5-7 like you said, as I have been locking out P/Mg/Ca which according to charts enjoy greater uptake towards 7. I know this is not ideal but they are in desperate need of said elements and I do not have access to individual supplements.

Do you think by adding solution of about 6.8-7 is ok? Also, you reckon the soil is roughly 6.2 right now. Is this inhibiting sufficient Mg, etc. uptake?

I will naturally raise/lower the pH towards and just above 6.5 per subsequent feed.
I know this isn't perfect as conditions are not the same throughout the soil and might even stress the girls out a bit more as they deal with local differences in pH, but only my measures of a couple decimal places.
I fed them straight away with a mild dose of 6.5 feed after flushing, of course the soil was water-logged and this pushed water out the bottom of the pots, but no problems it was cleaned it up.

I did the flushing in one session on Friday and I can't do any more as it takes quite a while for my 11L pots to dry out, they are still wet as of this evening but definitely getting drier. I don't want to encourage rot or asphyxiate the root mass. They have huge hole spaces for any dripping which has long since stopped. As mentioned I will not contemplate adding anything further until tomorrow or Monday.
Lu - I'd love to raise the pots to maximise surface area and thus evaporation - I can't - but the pots really do have large vertical holes at the bottom.

Once more: I don't have access to lime, I wish I did and will definitely have it to hand during the next grow. Right now all I have is the nasty, synthetic potassium hydroxide to balance the water/solutions I add. 70-80 days Barney's say, if I've done 41 days I have a good month left of flowering, so I'd definitely use it.

Its a cal mag issue. and check the charts. if im not mistaken cal and mag likes the 6.1 to 6.3 zone. givem an extra shot. i get this problem occasionally due to light nutrient solutions. calcium is more in veg and mag is more in flower. btw my tap starts out at 8.1 also make sure you let that water stand for 24 hours or so before you add anything to it!

I noticed that you mentioned something about your Cal is being blocked cause of low pH? Well does any of your nutes have sufficient Calcium in them? Are you using Cal/Mag supplement? Lack of calcium in the soil results in the soil becoming too acid dropping your pH. This leads to Mg or Fe deficiency or very slow stunted growth. If the crispy tips are still accelerating then the problem isnt fixed bro!

Magnesium (Mg) is found as a central atom in the chlorophyll molecule and is essential to the absorption of light energy. Magnesium aids in the utilization of nutrients, neutralizes acids and toxic compounds produced by the plant. Deficiency signs of magnesium are: Older leaves yellow from the center outward, while veins remain green on deficient plants. Leaf tips and edges may discolor and curl upward. Growing tips turn lime green if the deficiency progresses to the top of the plant.

Calcium (Ca) is fundamental to cell manufacture and growth. Soil gardeners use dolomite lime, which contains calcium and magnesium, to keep the soil sweet or buffered. Rockwool gardeners use calcium to buffer excess nutrients. Calcium moves slowly within the plant and tends to concentrate in roots and older growth. Consequently young growth shows deficiency signs first. Deficient leaf tips, edges and new growth will turn brown and die back. If too much calcium is applied early in life, it will stunt growth as well. It will also flocculate when a concentrated form is combined with potassium.

I would recommend that if you flushed her already, wait till she is ready to be watered again and I would flush it with water that is pH to 5.8 make sure you use at least a minimum of 3 times the size of your container.

Example: If your Soil Container is 1 gallon then you need to run 3 gallons of 5.8pH plain tap water through it. Then take 1 gallon and try to get some Cal/Mag mixed with your nutes. After you mix your nutes, pH that to 6.5 and run the whole gallon of nute mix through. Kick back and watch how your plant recovers and watch how fast she recovers.

Yeah I know people will say thats crazy but this is proven and how I feed my plants every feeding. I flush them and nute them every feeding. This is how Mother Nature does it when it rains outside. Why do you think after each rain fall outside it seems that grass,weeds,plants all look nice with new growth...

This technique of Making It Rain was proven, tested and created by Riddleme. you might want to check out some of his threads, https://www.rollitup.org/general-marijuana-growing/409622-truth-about-flushing.html or https://www.rollitup.org/newbie-central/316301-calling-all-noob-growers.html

Hope this helps

Peace All

BKB

Honestly thank you for all the quick replies, kind of you all.

Dirty and bekind - good points!

I just checked my BioBizz formulas and of course there is no Calcium. Fucking typical noob mistake (assuming it was in the mix)! Even more so when BunnyFace suggested that the BioBizz range is light in Mg/Ca when I started my grow thread way back, and that I might want to get some in case.

The Top Max bottle gives a run down of its ingredients (only in German... not even in Dutch despite it being a Dutch company... what the fuck is that about!?).

It has trace amounts of Magnesium (as an oxide) but no Calcium!
Grow and Bloom formula are simply rearrangements of NPK ratios, nothing else included! Meaning, there is no Calcium in my mix! So retarded!

Beyond fixing the pH which I think I am capable of doing - cheers bekind for the information - what supplements for Mg and Ca would anyone recommend for an organic grower?

I need to buy this tomorrow, I hope my local shop stocks something suitable. I think it has the Canna Mono range - as it stands organic or synthetic will do as I'm pressed for time getting the essentials to my babies. I'm so sorry girls, I didn't mean to starve you

thrash4ever said:

Honestly thank you for all the quick replies, kind of you all.

Dirty and bekind - good points!

I just checked my BioBizz formulas and of course there is no Calcium. Fucking typical noob mistake (assuming it was in the mix)! Even more so when BunnyFace suggested that the BioBizz range is light in Mg/Ca when I started my grow thread way back, and that I might want to get some in case.

The Top Max bottle gives a run down of its ingredients (only in German... not even in Dutch despite it being a Dutch company... what the fuck is that about!?).

It has trace amounts of Magnesium (as an oxide) but no Calcium!
Grow and Bloom formula are simply rearrangements of NPK ratios, nothing else included! Meaning, there is no Calcium in my mix! So retarded!

Beyond fixing the pH which I think I am capable of doing - cheers bekind for the information - what supplements for Mg and Ca would anyone recommend for an organic grower?

I need to buy this tomorrow, I hope my local shop stocks something suitable. I think it has the Canna Mono range - as it stands organic or synthetic will do as I'm pressed for time getting the essentials to my babies. I'm so sorry girls, I didn't mean to starve you

Click to expand...

If you cant get no Cal/Mag supplement PM me and I will send you a small bottle's worth and if you need Dolimite Lime let me know, I see that you have nowhere around you to get it, I will help you get some too. I would still flush your plant as soon as you have the Cal/Mag. It will give your soil a clean slate and fresh nutes with some Cal/Mag. Thats your solution bro....hit me up if you need help. I will try to help you as much as I know and if I dont know I will find someone who does.

I am a nOOb too bro....Whats great is how forgiving our girls are to us.

Peace

BKB

Thanks for the offer but I think it will be quicker to try to get it locally.
Grow shop is closed today, of course (used to be open today)

Hey man, also try letting your tap water air out afew days in abig bucket. This lets all the chlorine evaporate. That will kill some of the beneficial microbes . Good luck, jethead

Just want to say thanks to all again, and a follow up is here:

https://www.rollitup.org/organics/424203-quick-fix-calcium-magnesium.html

Bought the Canna Mono elements, let's see if that does the trick.

Here are some more photos focusing on the problems. Some are out of focus. Apologies, but it's so damn bright and hot taking photos right under my bulb.

The photos are arranged per plant.

Stringy on the left:


Fat girl in front left (minor problems):


Stringy in the middle:


Stringy on the right:



I am hypothesising that the taller plants expended all available calcium much quicker as they had to build a lot more stem. The two squat plants show little deficiency and are the ideal phenotype.

The brown leaf tips were grey, curled and crispy a few days ago but being OCD-ish about my grow I flicked the crusty tips off. There is brown scarring going on now.


Lastly - what do you think of a re-pot at this stage using the same pots?

I did a brief dig into the top layer of my soil and there is no root activity - about 3" of wasted space. I plan to add a fresh layer (of 3") to the bottom of the pots where the roots are literally crawling out of seep holes.
About one month left of flowering, I expect very little stress as I am just maximising the pot space for the roots to grow into with fresh Light-Mix.

i was in the shop the other day and looked at the canna stuff and it was too dear, looked like good stuff though. i ended up completing the bio range and getting alg-a-mic. contains good amounts of cal/mag and i have strted to feed it on the upper/lower leaves as a foliar spray and it seems to work well. leaves are colouring up a bit.
i would not advise to repot during flowering, i did it once at the end of flowering but its risky, they dont like to be stressed at this stage. the bio bizz chart you are relating to is only a guide. the plants dont really need as much nitrogen at this stage. i only use 1ml of grow with each watering. how often are you feeding the plants? they are only supposed to be fed once a week with that feeding schedule. i dont know if you have already but i made myself a chart and wrote down the date and what feed each plant gets as its very easy to forget who got what. not all of the damaged pots will recover but most of the mild yellow should recover, also after doing any flushing i always start with a mild nute solution so as not to shock them.
i did not read through all the post again so just going on memeory, if anything i have said is wrong or already said, accept my apologies.
the def will take a while to recify them selves and as long as you have the ph balanced now you should be ok, just no repotting.
what size pots are you using?
later
lu