High Soil PH and leaf deficiencies

C21H30O2

C21H30O2

New Member
Plants: 1 x Cream Caramel (auto-flowering) & 1 x Pineapple Express (auto-flowering)
Life span: 44 days since sprout, 4 weeks into flowering: Hopefully will live until 62-63 days.
Temperature: 23º-29º C (73-84ºF)
Average humidity: Veg 55% - Flowering 35%
Watering: every 2 days
Lamps: 250w CFL (dual spectrum) + 2 neon tubes 55w (dual spectrum).
Total light: 360w dual spectre (180w 2700ºK + 180w 6400ºK)
Soil: Canna Terra Professional Plus+ (with Perlite mixed in)
Nutes: GHE Biothrive Grow + Bloom
Feeding: 1 time every week, 2ml per liter of water.

Hey guys, my plants are looking pretty bad with yellow and brown leaves from bottom to the top. One of them also has some brown colors in the border of new growth and brown spots in older leaves.

I guess it's a deficiency of some sort... I read it could be a lockout because of high soil PH, since the runoff is always at 7 (or higher) when watering at PH 6.5.
I tried to lower the soil PH with water at 5.9 (using PH Down) but PH won't go lower than 7 anyway.

This morning I flushed the plants using PH'd water to 6.0 and the initial runoff came out at 6.2 (so I assument the soil PH was good around 6.4) but several hours later I checked the late runoff and again it was over 7 (so the soil PH must be well over 7). I also flushed 3 weeks ago because fan leaves started showing yellow spots and the flush solved the problem, so I'm hoping it will help this time but I have the feeling that flushing every 2 weeks is not ideal.

Is the deficiency caused by salt build up locking out nutrients? Am I not giving them enough food? What would you recommend? I really hope my plants will reach 62-63 days before harvest but it looks like they won't make it to 50 days

On a side note, as a bonus, I must say that half of the pistils are orange already, and the trichomes are ALL milky/cloudy. It's like if the plants were ready to be harvested but they are only 44 days old from sprout! Isn't it way too early even for autos?

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Hope you guys can help, as it's my first grow and even tho I read a lot I don't know how to help them Thanks in advance.
 
yarddog35 said:
Flowering looks good!

Here is a chart for nute intake, as per ph level
PH and Nutrient Uptake charts!
Click to expand...

Thanks yarddog35,

Those graphs almost make it look like a ph value of 7 is better than anything else...

If you have a high soil ph, is it good to water at much lower ph to correct? Say for example, your nutrient solution is at ph 6.5 and the runoff comes out at 7.2, so next time you water with 5.5 ph hoping the runoff will also be 1 point lower. Is that helpful or will it just make it worse because your soil ph is too high and your water ph is too low?
 
Looks like nitrogen deficiency.

malady_chart.jpg


Let your soil dry out a bit between watering. Every 2 days is too much and with fluctuating pH can also cause nutrient lockout which gives plants deficiencies. Yes, you're right if the pH in soil run off is higher, then your next feeding/watering should contain lower pH for balance. Normally plants in bloom uses up the nitrogen in the leaves during the final few weeks of flushing. The plant could use 2-3 more weeks before it is ripe, right now there are many white pistils even when the trichomes are cloudy/milky wait till there's at lease 20% amber before harvesting. Best to wait till the bud swell up some more to prevent airy buds after it's dried.
 
Twelve12 said:
Looks like nitrogen deficiency.
Let your soil dry out a bit between watering. Every 2 days is too much and with fluctuating pH can also cause nutrient lockout which gives plants deficiencies. Yes, you're right if the pH in soil run off is higher, then your next feeding/watering should contain lower pH for balance. Normally plants in bloom uses up the nitrogen in the leaves during the final few weeks of flushing. The plant could use 2-3 more weeks before it is ripe, right now there are many white pistils even when the trichomes are cloudy/milky wait till there's at lease 20% amber before harvesting. Best to wait till the bud swell up some more to prevent airy buds after it's dried.
Click to expand...


Thanks 12,

Looking at that chart, for me it looks like a mix of NPK deficiency in general, I just don't know if it's being caused by not feeding enough, or by a roots lockout. And if its a lockout, is it because of overfeeding and salts have built up in the soil? I didn't know that Ph fluctuations can create a lockout too, that would make sense in my case as I water at Ph < 6 and the runoff is Ph > 7.

I've been watering every 2 days because the pot starts feeling light at that point. I figured I mixed a lot of perlite in the soil, and the high temp and low humidity were causing high evaporation thus contributing to salt buildup. I really have a hard time finding the correct watering/feeding schedule for my setup :/

As for the harvest, yeah I'm totally hoping I can give them 3 more weeks, at least 2, but I'm just confused that there's so many orange pistils and all trichomes are cloudy so early. I would expect white pistils and clear trichomes at day 44 since sprout (even for an auto).
 
Also keep in mind that this is an auto plant so they'll finish faster than most strains. So the deficiencies could be part of the automatic system the plant is going through. Best time to water is morning feed (within an hour of lights on). Try increasing the nute dosage by 2ml - 5ml per gal and see if it slow down the yellowing.
 
Hey 12, I've read that for indoor soil grows I could just forget about controlling Ph levels... and the General Organics site says that when using these nutrients it's unnecessary to adjust Ph of nutrient solution... Could I just stop worrying about pH and give light feedings every other watering?

Also, would you recommend using CaMg booster to the solution? I was thinking of buying some.

Oh and btw, I noticed you're nominated for grower of the month (you got my vote :grinjoint:)
 
It's not that we don't trust the nute company saying pH adjusting is not needed/required, most of it is also the water we use and that varies from location. Checking pH after mixing nutes really pays off. That will put the end to worrying. You could feed light but from the look of the plants require more. Are you using RO water or tap water? If RO add some calmag get it up to 50 - 200 PPM before nute and if you're using tap water no calmag booster needed since it's already in the water and from your nutes.

Oh you noticed. Thanks for the vote. :}
 
You deserve the vote man :high-five:

I'm using tap water normally. Ph is about 7.3 right off the sink but I've been lowering it to 5.8 (adding a few drops of phosphoric acid) trying to correct the runoff Ph which is around 7. I do the same with the nutrient solution, lowering it to 6.0.

Sometimes I filter the tap water with brita jar, which already reduces the Ph to 6.7 and I can use less drops of acid to correct the Ph... but I don't know if this brita filter might be taking away something good from the tap water so I only use it sometimes.

I guess I could just make sure that the solution is at 6.5 and not worry so much about the runoff?
 
Do you leave the tap water sit out for at least 24hrs? The chlorine may cause disturbance within the medium killing off good bacteria. No need to filter it with anything the only concern is chlorine. Been using tap water forever and it's fine as long as let it sit out for a day before use.

Yeah don't worry too much on the runoff as long as it's not over 7 you're fine. Feed plants a little more acidic in premix to compensate the neutral runoff, so pH 6.5 for premix is good! :thumb:
 
Hey 12,

I guess that if chlorine is the main issue with tap water, then I should always use brita filters since they apparently remove it:

Treatment Plants add chlorine at P.O.E. (Point of Entry) to remove germs and ensure they don't re-appear while the water travels many miles through the pipes to your tap (P.O.U. ...Point of Use). While the amount of chlorine added is regulated and not considered dangerous, it does impair taste and odour plus there is a definite chance that it can combine with organic compounds to produce chlorinated hydrocarbons that may lead to health related problems. The activated carbon in the Filter will reduce the chlorine by up to 99%.​

But as the same time it reduces chlorine it also reduces Ca and Mg. Would it be better to use brita and CaMg booster or to let tap water sit for 24 hours?

The BRITA water filter cartridge only partially removes the hardness from drinking water. This part is temporary hardness, which causes scale deposits during cooking. It does not remove all of the minerals from the water. It reduces the concentration of calcium and magnesium with cation ion exchange resins, but theses substances are not completely removed as in desalination systems or industrial plants that use reverse osmosis or distillation processes, for example.​
 
Easiest way to get chlorine out is let the water sit for 24hrs. Fill up a few bucket worth and let them sit. Removing chlorine with filtering system in your case, Brita, it will also take away most of the trace minerals as you have mentioned. Letting the chlorine evaporate naturally will leave all the trace minerals alone. You could add calmag to the filtered water, however not knowing how much calmag is already in there will do more harm.
 
C21H30O2 said:
Thanks yarddog35,

Those graphs almost make it look like a ph value of 7 is better than anything else...

If you have a high soil ph, is it good to water at much lower ph to correct? Say for example, your nutrient solution is at ph 6.5 and the runoff comes out at 7.2, so next time you water with 5.5 ph hoping the runoff will also be 1 point lower. Is that helpful or will it just make it worse because your soil ph is too high and your water ph is too low?
Click to expand...

I disagree with altering your feed/water ph to correct soil ph issues. Give the following tutorial a read and you will see how to amend your soil to address ph issues....

How Can I Raise or Lower the pH of my Soil Mix?

FYI...Dolomite lime should be part of your soil mix, imo, as it acts as a ph stabilizer throughout your grow.
 
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