Soil PH too low

[Koskesh]

Hi all, Cannuck Jack Herer grower having some issues lately.. Thought I had necro spot disease carried by thrips, but realize now that it's a def/lockout/tox problem. Stats:

SOIL:

How long has this problem been going on? 2 crops
What STRAIN are you growing? Jack Herer
What was the establishing technique? (seed or clone?) clone
What is the age of your plants? 6 wks and 10 wks
How Tall are the plants? 30" and 60"
What PHASE (seedling, vegetative or flower) are the plants in? flowering
What Technique are you using? (SOG, SCROG etc) 4-5 foot single tops
What size pots are you using? (Include how many subjects to pot) 8" pots, 1
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?) Lambert professional growing medium (peat, perlite, vermiculite, lime)
What Nutrient's are you using?How much of each with how much water? How Often? *Knowing the brand is very helpful* Optimum Hydroponix
What is the TDS/EC/PPM of your nutrients used? 600-1200
What is the pH of the "RUN-OFF"? 5.3 to 5.6 (lol)
What method of pH test was administered? Using Strips? pH pen? digital pen
How often are you watering? every 2nd day 1 liter
When was your last feeding and how often are you feeding? every other watering
What size bulb are you using? 1000w hps
What is the distance to the canopy? 12-18 inches
What is your RH Factor? (Relative Humidity) 50%
What is the canopy temperature? 28-34 c
What is the Day/Night Temp? (Include fluctuation range) 20-28 c
What is the current Air Flow? (cfm etc.) not sure. using cool tubes, 700cfm every 3 lights.
Is the fan blowing directly at plants? the oscillators are
Is the grow substrate constantly wet or moist? no, i water when pots are light, enough for 2 days
Is your water HARD or SOFT? dunno, ph is 6.8 to 7, ppm 70
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? tap
Has plant been recently pruned, cloned or pinched? no
Have any pest chemicals been used? If so what and when? neem oil only, 8ml/L foliar once a week (2L for 120-140 girls)
Are plant's infected with pest's? thrips, very light, might even be gone, still observing.

additional info: I don't add extra lime or compost to the mix, which I'm reading is a problem. I always adjust my water ph to 5.8, whether feeding or not, since I was told this is a soil-less medium, and I always used 5.8 for these in rockwool, etc. These 2 things combined are obviously the main aggravating factors. Not sure how the ph would fall well below what I give them, but meh.

One room is 6 weeks into flower, runoff ph is only 5.3, ppm is off the scale. Only 2 weeks to go, they will make it, flowers look healthy enough though smaller than usual, but leaves are frying. Looks like I'll only get 20gr instead of my usual 35-50 per plant - is there any way I can get them to eat something before the chop? lolz. I've been giving them plain water ph 7 for a week now, no change in runoff

The other room is 2 weeks into flower, runoff ph is 5.6, ppm 1400. They are just starting to show signs of def, some spotting, frying, and general unhappiness. Also been giving these plain water ph 7 for a week no change in runoff.

I guess the big question is how to quickly raise the ph of my soil so they can eat, and I'm gonna scrap my 2 week veggers and start fresh.

Should I add lime to my mix when I build my pots, even though it's already in there? compost? Guess I should use soil PH parameters not soil-less, regardless of the label - like 6.5 not 5.8

I apologize in advance is this is a long annoying post, if you couldn't bear to read it feel free to ask questions, all help is appreciated.

 

[Koskesh]

I've always used promix hp without these probs, but I also wasn't adding this ph down all the time. I found out the stuff I use now is the same as black bag regular promix, not HP - bad? I used to only get about 1lb per light (12 plants) but my first 2 crops using the new stuff and ph down I got almost twice that (8 lights, 135 plants, 14.75 lbs)!

Then all of a sudden these probs. Now I'm back down to 1.25 per light of lower quality product - that's what I found strange, figured it wasn't me since I hadn't changed anything, and blamed the thrips. The problem is persisting now that they're mostly if not completely gone, which led me to the runoff test, etc.

weak.

 

[sirgrassalot]

I have some answers but I'm waiting on this post for a while. I'm always interested in the extra lime & pHing bull shit to come out. The HP balances the pH to 5.2 - 6.2 adding my nutes brings it up 6.0 - 6.8 while my bloom nutes drop slightly 5.2-6.0 with my water @ 7.0 - 7.8

Can you tell us exactly the mix you're using & where you've read Lambert needs extra lime

http://canadianpeatmoss.com/detailpeat.html#P2

The freshest Pro-Mix comes in white bags now, they used to be in black bags but you would need to know the type. On their list BX is first HP is second followed by the others.

http://www.premierhort.com/eProMix/Horticulture/Products/GrowingMediaCat/Regular/fPeatMoss.htm

 

[Koskesh]

it's lm-3 the all purpose. i didn't think i need to add lime since it's already in there... if it starts out about neutral, and i'm watering 5.8, how can it get to 5.3? unless i killed the lime if i was supposed to water with 6.3-6.8. But if that's the case, why do they call this soil-less lol if i have to treat it like soil it's fuckin soil

 

[sirgrassalot]

why do they call this soil-less lol if i have to treat it like soil it's fuckin soil

You got me there but you're correct. It's lighter when dry & not as dirty. LoL

Without finding the pH of LM-3 General Purpose Mix yet it appears it's like the BX using vermiculite rather than all Perlite like the HP does. If it looks like you could add some extra Perlite to it, do it. I'm going to search the pH balance to see if it's the same as PM. Treat it like the PM if you've had success with that (most peeps do) can it be worse the pHing mess you have now?

Plain water in Triple Mixes is a NO NO in my book. You can lock the plant up for up to 2 weeks before they get growing again but you don't stop feeding. You leach them with a 10-25% solution. Final 1 or 2 waterings plain tap only. Now that's Not how to treat soil.

 

[stinkyattic]

Some issues:
-Hydro-specific nute in soil? Likely to buffer pH low enough to leach lime right out of your soil.
-4 foot plants in 8" pots? Too big. You need to put them in larger containers to avoid the soil chem problems that come along with being rootbound. Re-pot every 5 weeks or so to avoid problems stemming from soil lime being used up in that time.
-I'd water at pH 7 with some calmag up to ~250ppm too, to help remedy this for this crop, and in the future, work on your re-potting schedule to manage the balance between plant size and available soil lime.
-your temps seem high

 

[Koskesh]

Plain water in Triple Mixes is a NO NO in my book. You can lock the plant up for up to 2 weeks before they get growing again but you don't stop feeding. You leech them with a 10-25% solution. Final 1 or 2 waterings plain tap only. Now that's Not how to treat soil.

rgr on the leeching, they're defo getting locked up as early as 2 weeks veg

 

[sirgrassalot]

rgr on the leeching, they're defo getting locked up as early as 2 weeks veg

Listen I thought it was hog wash until it happened to me & the fix (leaching) works.

 

[Koskesh]

Some issues:
-Hydro-specific nute in soil? Likely to buffer pH low enough to leach lime right out of your soil.
-4 foot plants in 8" pots? Too big. You need to put them in larger containers to avoid the soil chem problems that come along with being rootbound. Re-pot every 5 weeks or so to avoid problems stemming from soil lime being used up in that time.
-I'd water at pH 7 with some calmag up to ~250ppm too, to help remedy this for this crop, and in the future, work on your re-potting schedule to manage the balance between plant size and available soil lime.
-your temps seem high

-i've always used these, without a prob. they bring ph to around 6, which i then lower to 5.8 - i think i should raise it instead lol to like 6.5?

-yes the plants are tall for these pots, they are stretching more than usual in prebloom they normally finish around 3 ft or 3 1/2. they are not rootbound, these problems are also affecting root development unfortunately. stretchy, badly rooted, roasting leaves, not good. but you're saying the lime CAN be used up which is news to me - if i start using ph 6.5 instead of 5.8 wouldn't that help

-rgr on the cal-mag to 250ppm, guess i should also start feeding again?

- my temps ARE high atm, been warm here. will be better soon



thanks for the replies so far guys, very helpful

 

[sirgrassalot]

2 weeks in there's no run out of lime issue if at anytime in a normal grow. You know farmers lay their lime in the fall. They hope all the winter & spring run offs take their lime away so they have to use extra. LoL They do it because it takes lime up to 3 months to become totally effective although there is some short term usefulness.

I've inquired about the pH balance, will see if it's 5.2 - 6.2, 6.2 saturated for seven days.

 

[stinkyattic]

-i've always used these, without a prob. they bring ph to around 6, which i then lower to 5.8 - i think i should raise it instead lol to like 6.5?

Yeah, you should bump it up to the correct range for your medium, so 6.5 for soilless or 6.7 for soil. That's important and will help you immensely.

RE: farmers laying lime in fall; that's a good time to lay it because as you say it has time to interact with the soil. But also remember that the pH and ionic strength of rainfall, even if acidic, aren't close to that of nute solution, so it's a different game.
I don't see any timeline for how long the plants have been in these pots and am going by size to assume that it's been too long.

 

[Koskesh]

I don't see any timeline for how long the plants have been in these pots and am going by size to assume that it's been too long.

i make my clones in jiffy peat pellets and they go right to the 8" pots for the duration - 11-12 weeks including veg. I know that's not ideal by any means but it's worked so far - maybe i should start using 4" in between...
usually 3-4 weeks veg in the 8" brings them to 25" and 8 weeks later they finish at 35-40" with 35-50gr each of really nice nugs, thick, hard, frosty and stinky

 

[stinkyattic]

Yes, I really do agree that an intermediate pot size will help you. Managing re-potting is IMVHO the single most important concept to master when it comes to growing in ANY peat-based medium.

 

[sirgrassalot]

Transplanting correctly can only help & with the triples you're adding 2 limes automatically.

 

[Koskesh]

cool, thanks, will do that from now on. maybe ill go to 4" for 2-3 weeks then 8". should i add compost or anything or just the mix (it's airy enough as is, but adding compost will require adding some perlite)?

so far for next round we got:
repotting
ph 6.5 not 5.8
leech instead of plain water
cal-mag to 250ppm before additives

again thanks, much appreciated. still unsure what to do to the 6wk flower and 2wk flower ones that are already locked up.. just resume feeding at the new ph with cal-mag? i'm off to the store soon to get this stuff

 

[sirgrassalot]

again thanks, much appreciated. still unsure what to do to the 6wk flower and 2wk flower ones that are already locked up.. just resume feeding at the new ph with cal-mag? i'm off to the store soon to get this stuff

Here's what I would do.

The ones locked up, if they've not been fed in the last watering or 2, feed with your regular full dose, next watering leach 10 - 25%, determine how much food they need on the third watering & give them either 10-25% or more up to a regular full dose & repeat these steps. You never want to overfeed at anytime. Maybe run them for an extra week this grow if possible, check your trichomes for extra growing time. The cal-mag I have but it's never been opened. I'd keep my pH higher than lower but I don't have a grasp on the nutes you're using. Your water seems to be fairly good (Canadian Eh), if it were me I'd use a similar nute as PBP bloom ~ DNF booster & not pH anything.

I just read you want to add compost, that would change things.

 

[Koskesh]

ok i'll start the feeding again with leeching, will add cal-mag to 250ppm since my water is so clean, and going a week longer is no prob, they are a little behind anyway. the only thing that will make me chop early is impending death lol

these are my nutes: http://www.optimum-hydroponix.com/

i don't want to add compost, just wondering if i should. dudes at the grow store may be tards, but told me i should add some sheep compost to the mix - that may just be complicating things for nothing. I think if i fix my ph and micronutrient issue things will return to sweetness

cheers

 

[stinkyattic]

I think at this point adding compost would be counter to your needs. I think you are right. If you want to add some organic goodness, I'm going to suggest adding TopMax. There are a couple things in it that could benefit you: Humic acid, an organic acid that buffers at pH 6.9 and prevents unwanted fertilizer interactions. Carb synthesizers. Carbs. Goodness. lol! But it's not strictly necessary and simple is good.
Good luck.

 

[Koskesh]

ok gave them all some cal-mag, tested on one and been 24hrs with no immediate negative reaction so dosed 'em all lol

uploaded a pic to my gallery, from last time things were still good - just so you know i'm not a shwag farmin' nublet haha

one funny thing, the ones i flushed for runoff tests are lookin much worse than their sisters, no biggie i'd have scrapped 10 times that just to get a handle on the problem. just thought it was strange so i'm mentioning it

 

[Koskesh]

TopMax looks sweet but is it ok to mix organics with chems? i've always wanted to try fully organic but am afraid i won't get as much weight - T or F? i don't really want to make my soil and have to wait 2 weeks to use it either - no space to waste for ripening mounds of dirt lol

oh and sorry for my lack of caps, punctuation, etc - i assure you i'm not illiterate, just lazy