Is this a nute deficiency?

[Stone420]

Shown is a Northern Lights Auto deep into flower at 9 weeks old. Looks like a nutrient deficiency by the light intervein coloring on her sugar leaves...or is this end of life discoloration?

I'm using Ocean Forest soil, but PPM runoff indicates her organic free nutes were used up a month ago. I'm using Advanced Nutrient base nutes with Ph Perfect technology which is said to buffer ph to prevent lockout. After adding nutes, I adjust the nute water to 7.0 and get runoff between 6.2 and 6.3. Going in the ppm is 1300 and coming out in runoff, I last tested at 990.

Since she is 2 or 3 weeks til harvest, I don't want to make any radical moves and really don't see the need to flush with numbers this good.

 

[Waira]

don't adjust AN nutes, that what the "self-buffering " is about, and applies only to solutions really... but once in the pot all bets are off! Too many other strong influencing factors in play,...
I'd ease up on the ppm's, you may have a lockout starting... symptoms look like Fe defc., maybe Zn,....
Get a reading on the in-pot pH if you can... your inputs are not reflective of what the pH is in the pot,... You'll need a good soil pH probe for this, like the Accurate 8 -> hsoil: (long probe unit in this icon)... it's the same unit offered under different brand names too, likely cheaper...
...run-off is not a reliable measure of in-pot pH, way too crude, but in a pinch, it can at least indicate if things are out of whack in there... you must use RO/Di very low ppm water to do this crude test though, unadjusted too BTW,... nothing that influences/buffers pH can go in for this test, or it skews things even more,...

 

[Stone420]

@Waira , I'm especially interested in what we are discussing about the soil ph - and how to get more accurate readings. I often thought run-off water (to test for ph) was pass thru water, and lots of the run off simply passes between the soil and the side of the pot. I totally agree a soil ph tester will be valuable, but I always had folks say they are not accurate or reliable. I'm glad you brought this to my attention.

I see the long probe Accurate 8 meter on Amazon for like $85 prime, but there is an identical gauge called Gain Ph gauge for $59. (There are several other meters that look identical as well) Pictures show the two gauges to be identical, so this must be the different brand name you mentioned. If you have any input on the meter before I buy it, please holler, then I'll order. I appreciate your advice.

 

[Waira]

it is indeed the same unit, same Chinese factory! I don't know why the CPW A-8 unit has gone up like $30 recently? I paid about $55 5 years ago,... The other cheapo skinny-ass probes, combo meters (A8 does have a built-in moisture meter, semi-useful) are lousy, tested a few against the A8 and they sucked! You can spend bigger $ on a trick Blue Lab unit, which works basically the same as a pH meter (electrode bulb type) just modified a bit to take the beating... of course that come with the same PITA care that all good pH meters need, proper storage solution, calibration 7.0 and 4.0 soln.'s.....
Problem with run-off is this: think of the soil as like a coffee cone filter,.. everything concentrates as it passes down through the filter, so what comes out is more concentrated than what it is generally overall,...that conc. skews actual pH (pH can vary some in the pot, in and out of the root zone, and the depth, same reason)..... This applies to EC/TDS ppm's too.... you're in soil, right, not coco? that's a whole different gig there,...
Slurry testing works well too, but it's a beating to do in an established pot, plus you're mining through roots to get that few Tbs.' of soil out of the middle zone,... ... far better to use that right out of the bag to confirm pH is OK,... test is 1 part soil, 1-2 parts RO/Di water, mixed and let sit for 1/2 hour, then strain off liquid and test with pH meter... I see both 1:1 and 1:2 soil to water used ... i do 1:1 or so because at 1:2 the dilution factor isn't like what's in the pot, right? --that would be dirt soup- ....
testing the run-off for ppm or EC can be helpful, if you've kept track of what the input ppm's have been, water + actual nutes,... and the same conc. thing applies here, huge ppm's are not what's in the pot all over, but if you get stupid big #'s, likely you have a build-up problem that can trigger several issues with nute availability, pH and uptake.....

 

[Stone420]

I cant thank you enough @Waira, for the time you took to share your input. I am truly appreciative to get this detailed information. Most new(er) growers are trained to test run-off since that's fairly simple to do, and of course that method is better than nothing I suppose. But given the accuracy factor, I think you have me on the right track by purchasing a reliable pH soil tester like the Accurate 8 or the Gain which I what I'll select.

I'm currently growing in Ocean Forest soil amended by Perlite. This nute charged soil seems to "have a mind of its own" and is pretty hard to properly manage nutes with my lack of long term growing experience indoors. I use Advanced Nutrients and their reps have pretty much warned me off of OF, so I plan to shift over to Pro-Mix HP next indoor grow. My thoughts are that I can manage my nutes much better myself than letting the soil decide when and if to break down and make nutes available. In other words - I would be in charge of nutes...not the soil being in charge.

I currently use an Apera pH pen and a Blue Lab EC/PPM pen. I think the addition of my new Gain pH soil tester will be invaluable as I learn and grow. I'll do a 1:1 soil slurry test with the ProMix so I can get a beginning baseline on the pH of the medium. Going forward, I'll have the Gain meter to keep tabs on the medium to make adjustments if necessary. BTW...The reps at AN strongly support AN nutes to be used in ProMix HP. They are not too fond of OF due to the lack of control this soil offers.

Again, @Waira, thank you for the great mentorship and guidance. Together we learn and grow.

 

[Waira]

Cheers Stone', happy to help! ...... I forgot to mention there's an "improved" run-off test method and calculation in the colored section above this one; as you'll see, that calls for testing run-off using RO/Di water, but any very low ppm water is fine, like drinking water, or those self-fill machines (much cheaper),... A TDS/EC meter isn't necessarily something you'll use every day with a true soil grow, but when you need that vital info, there's no substitute,...
There's also a definite method for using the A8 unit properly too, to get the best readings:
-- test soil that well moistened, not freshly watered or especially freshly feed (more skewing), nor any kind of dry.. just the way these type of meters (bi-metal tip) work....
-- That tip needs to be kept in good shape, wiped clean with damp, clear water paper towel or something before and after each use and stored to keep corrosion and moisture damage at bay (some folks I know stuck it into solutions, and guess what? )... keep it someplace nice, inside, not exposed to elements. My client ruined his in less than a year keeping it in a outside storage closet sweat-box with the other landscaping/garden chem's!
-- let it sit for a couple minute to stabilize; when first putting it in, it'll peg out right away as it slides in, so don't be alarmed by that.... never let it sit for long either, corrosion and long term moisture exposure will ruin it,...
mine is 5 years old i think? Still works well, and i have tested it a few times against a slurry test, with 2 different soils,.. all readings withing 0.2 of each other, the margin of error this probe (wrongly called a meter) is rated for!
good of AN to wave you off of those dogshite soils, especially OF! I have tested that soil in the low 5's pH right out of the bag- That is give-fuck-all quality control right there!
Instant shitshow, bugs and all,....
ProMix is great, but keep in mind this is a soilless medium, akin to Sunshine Mix,... coco is soilless too, even the slightly amended stuff should be treated like straight coco... a very peculiar medium, a lot of do's and don'ts, easy to screw up, bitchy to fix and manage it's fragile CEC (cation exchange capacity) properties.... once wired, it's amazing for it's beneficial properties, but that's running it more like hydro, not a true soil which it is NOT... treat it like it is, and things will go TARFU soon enough,... So, I suggest you stay with soil, because soilless mixes are devoid of nutrients, more to manage, less forgiving generally,... Look for Roots Organic original, 707 is fairly hot... Sanctuary Soil if you can find it is very nice,... Don't get me wrong, ProMix is good, just be aware that feeding is entirely on you, there's no nutrient "buffer" like true soil has, is all I'm saying.... In any case, use inoculants (Recharge is a fine value from what all it has in it), a Si supplement (many benefits to Si, be aware though that it raises pH), a micrinutrient supp' (Earth Juice Microblast is my fav'), and humic-fulvic (BioAg makes the best stuff, dry Ful-Humix 100g bag is cheap and will last for years, very little is used)... Pure spoiling is Ful-Power, a liquid pure fulvic, which has several advantages for in-pot use and foliar... Check out the reference section for articles on h-f's and chelation, as they are linked,..... let me know when you're out of $ so I'll shut up already!
...

 

[Stone420]

You got my gears turning @Waira regarding soil pH testers, and with Amazon Prime next day shipping, I made a second buying choice. I got in the long probe Gain tester and tested it in several soil samples. It acted weird and the needle pegged to the right and stayed there. It acted like this several times, then wouldn't respond in any way. I question some of the Chinese Q/A standards, but no biggie as it was easy to return for replacement or get a refund. After some thought and reading, I sent the Gain back and ordered a Blue Lab soil pH meter that tests multi-media sources. I'm familiar with using general purpose pH pens (Hach, Apera, Blue Lab) and have calibration and storage solutions readily available. I'm confident with Blue Lab products, and while I ended up spending more to go this route, I am 100% satisfied and will have unlimited uses with this pen. The meter arrived and I used it several times yesterday with optimum results. It calibrates easily, locks on very quickly and seems exceptionally accurate tested against other pH pens. If the probe goes bad over time, this unit has a very reasonably priced replacement pH probe.

 

[Waira]

nice! Sorry the Gain was a POS, I'm not sure what's going on with the A8 units these days,.. why CPW, the original company offering it, and the price jump, but it makes it a rip-off, not a bargain.... and if the cheaper different brand name ones are crap, factory 2nd's or something, that explains that- ... foooooock,.... it kills me because mine is like 5-6 years old now, still checks out OK,...... but it's moot now! You say the in-pot pH is OK? What is it?
How are the symptoms? Did you get a micronutrient supp' yet?
About the run-off, going down the pot sides,... shouldn't happen much unless the soil gets dry and becomes hydrophobic which is common,.. a wetting agent will fix that! I like Coco-Wet,.... this is also key for use when doing a foliar spray; it takes the surface tension out of the water.solution you're spraying so it coats and sticks better, instead of beading up... spray underside of the leaves in particular, more stomata there.... you can still do this carefully with the micro' supp' if you like,... let me know....

 

[Stone420]

*** You say the in-pot pH is OK?

I love this new Blue Lab pH soil meter and probe! Amazon took the Gain back w/o any questions at all, and the refund applied to the Blue Lab unit. I did 7, 4 and 10 pH calibrations and it dialed in perfectly. I tested some water samples, then compared to my freshly calibrated Apera pH tester to find they are reading identically. Yeaaaaa! I have tested the soil in tomatoes, herbs, houseplants and everything I can find to get experience with the meter. I am totally happy with this meter!!

**I tested my Northern Lights plant soil to find the pH is 6.3, so I consider this to be pretty well in the sweet spot. The plant has glossy clear trichomes that are just beginning to turn milky, and I saw one milky trich on her calyx that was tinging amber. The plant is 10 weeks old today, so give or take 2 - 3 weeks and she'll likely be in the chop shop. I'm giving her some light bud enhancers to finish up, but she seems really balanced heading into the home stretch. I think what appeared to be a nute deficiency may have been signs of age and maturity. And even if there is a bit of lock out going on, considering she is so close to harvest, I'll just let her ride it out.

I still hope to have the opportunity to discuss soils with you and the forum for my next indoor grow. I have a Blue Dream photo that is two weeks old in her Solo cup. She needs to be moved into a 1G transition pot pretty soon, so I need to decide which way to go in the next day or two. I have a full bag of Happy Frog soil, a bag of earthworm castings, perlite and a bale of Pro-Mix HP. I don't really have time to buy any other soils, so I need to use what's on-hand. I may mix Pro-Mix HP with an amendment of Happy Frog to give a light nute head start. I'll make a 1:1 soil slurry to test pH of the mix, and if the blend looks to be acid, I can work in some dolomitic lime as a buffer. Would like your opinion before I up-plant this Blue Dream seedling. Thanks!!

 

[Waira]

excellent! .... When checking the trich's, looks at bud calyxes only not sugar leaves, they tend to mature out faster,.. and look at bud all over, get a "plant average" if you can, and also see if the uppers are more ripe than lowers, a common thing; partial harvest is the way to go there....
For sure, some fade is good in the leaves, this tells you reserves are getting tapped into, clearing out the extra's which can make for better smoke...
Hmm, well I'd steer you away from soils altogether, but HF is the lesser evil of them,... it milder, usually better cooked vs OF which is dogshit, avoid that period! That, and off pH, so check that HF well, OF is often badly acidic, HF can be too! If it checks out, either is fine, just keep in mind ProMix is soilless, nearly devoid of any nutes, just some lime mainly for buffering,... this means you feed by week 2 at the latest, weakly at first, or very lightly preload the mix when you make it up.... HF you can feed lightly by week 2,... I say that because no bag soil of this type is nutritionally complete and balanced, best to have some food on the table to maximize their growth....