edit: measurement error, see correction in subsequent post.
It would look something like:
Overlaying it invalidates the y-axis ,though.
The slopes of two linear equations illustrates the similarity in the target PH range. 3.02 vs 2.99. Drift from alkalinity is possible.
There are a bunch of little details Id like to discuss, and that drift might change things some, but the elephant in the room is that Mega Crop has virtually identical buffering compared to Jacks. It may even have a slightly better/flatter curve in the key range.
To me that strongly suggests that the organics (or something) in Mega Crop are a key factor in the differences in the PH stability many people see between the two. It looks to me like the reason is not due to any buffering magic, but rather to bacteria liking to eat Mega Crop and not liking to eat Jacks.
edit: measurement error, see correction in subsequent post.
It does appear more flat at lower PH but Iād say equivalent at the moment. There is a some uncertainty in the measurement and weāre talking about a small difference.
Iām suspecting that is one likely scenario and it lines up with some of your experience. Also, occasionally, weāve seen precipitants in the MC. We havenāt had a good identification of whatās precipitating (and why) but it could also cause PH shift. Manufacturer has noted that precipitants are likely organic in nature.
The drift on the Jackās stands out here. If this is typical, itāll throw people off. Something with alkalinity, perhaps. Something else we havenāt figured out. Or, something wrong with my method.
edit: I donāt think the offset was quite right, this is a better view as overlayed and zoomed in (starting at 5.8)
Similarly, did a quick titration of the Jackās RO formulation at 1.7EC in RO water being stirred.
The components were prepared for 1 gallon using:
500ml was adjusted by dilution to the target 1.7EC. The solution is transluscent green-blue up until around a PH of 7.5 after which it starts to turn cloudy. You can see the slope change slightly as precipitation occurs.
The RO formulation show minimal drift with a low starting PH. Since drift was low (about 3/100 of a PH after an hour), I terminated collecting data early:
Buffering comparison against MC:
By the way, this stuff smells like dirty socks.
Hey @Northern_Loki, what is your take on the Jacks? I have never used it, but this run right now will be flowered with it.
Veg is taken care of but I have decided to try Jackās for flower.
im not using the 321 formula, but rather 2 different powders from them I will mix to get my wanted ratioās.
Hoping to find it is a decent fully complete food. My last run was with bargain basement nutes that gave me my values, but did not want to stay in suspension and was a PITA to deal with that. Results were outstanding however, so hoping Jackās will do me as well.
There has been a lot a praise for the Jackās recently. I havenāt used it yet and am just evaluating the different formulations to get a feel for how itāll might act in hydro. Particular to this thread is how it buffers against PH.
They have a bunch of ānewerā formulas in addition to the 321 which may be of interest as well.
So, Iām afraid I donāt have first hand practical use with the Jackās at the moment and I havenāt dug into the micronutrient balance of 321 either. My limited glance is that it looks fine. Some folk are moving in that direction due to some of the pitfalls of MC in hydro.
There are several individuals that do have practical experience and perhaps theyāll chime in. Some folk have started a thread on it over here, as well:
Been to it, mostly running 321, which I do not want to run. Guess I am about to find out. Im pretty vocal, so either way it works out I will document it in my thread as I go.
From the titration, Iām seeing a significant amount of slow drift initially. Wasnāt clear if youāre using 321 or some other Jacks? Did you happen to notice that drift if using 321?
No no, never used it before, and not going to now. I will be using their 10/30/20 for early n mid flower, then mid to late flower it mixed with their 5/12/26 to fatten up K some in later flower . I like certain NPK RATIOās in my grows, these 2 nutes allow me to mix to achieve those numbersā¦
No calmag, nothing else extra, NOT GONNA PHā¦have not pulled my PH meter out of the drawer on over 5 years.
Gotcha, youāre looking at their bloom and enhancing it with some 321 Part A to finish.
OMGā¦YEAH, someone understands!! EXACTLY!!!
early flower @ 1/3/2ā¦,mid flower @ 1/3/3ā¦late flower at 1/2/5 or so
Your method sounds good to me, but I wonder if i might be good to test your water all by itself for PH drift?
I suspect the alkalinity/c02 drift thing will vary - maybe a lot - from one location to another and possibly also with the seasons or depending on rain, treatment from a city, re-charging water softeners, etc etc.
Im not sure how we can narrow that down for people. They are just going to have to do some testing on their water to see how it reacts.
IIRC, when I did my tests, RO water was very slightly more stable than my tap water - maybe - but not enough to make a real difference. Plus, my tap water changes depending on the season or how much rain we have had - Im on a well.
It still seems a little odd that the Jacks had so much drift when the Mega Crop didnt. Were they both started/tested at the same initial and final temps? Same time for the RO water to equalize with the atmosphere?
I dont actually expect to see all that much change just from the alkalinity - at least not based on the level of aeration you were using - which was basically just gentle stirring? I wonder of the Jacks was still dissolving maybe? It took forever for it to dissolve for me.
Im ramblingā¦
I canāt. Or I should say, donāt want to risk the probe. It pure RO water with exceedingly low EC (unmeasurable with conventional probes). Iām afraid an extended drift test would quickly leach the probe to itās death. Intermittent spot checks puts it near where one would expect it, ~PH7.
To me, this effect looks to be inherent in the formulation of 321. Follow-up evaluation of the same source of water using a different formulations has not shown such dramatic drift.
With that said, it doesnāt rule out something went amiss with this particular test and, as such, Iāll be taking another look see. Iām considering two possibilities, a) the stored RO water intermittently contained high levels of dissolved CO2, b) carbonates are included in the 321, c) some combination of the two.
edit: Also possible that the probe needed re-hydration, it was sitting in storage solution for an extended period of time. Letās see what the follow-up test says. So, d) probe hydration problem
Re-running the tests on the 321 and Iām not seeing the initial drift any longer.
It was probably d, āprobe hydration problemā or a bubble in the probe.
So here is the revised information.
The components were prepared for 1 gallon using:
500ml was adjusted by dilution to the target 1.7EC. The solution is clear up until around a PH of 7.5 after which it starts to turn cloudy. You can see the slope change slightly as precipitation occurs.
Drift, terminated measurement early due to minimal noticed drift:
Buffering comparison against MC:
Sorry for the slow replies - Im still not at 100%.
If anything, the Mega Crop actually looks even better on this plot than it did before as far as the flatness of the curve and the relative slope compared to Jacks.
Could you zoom in on the area between say 5.0 and 6.5 or so? Thats the region most of us are primarily interested in.
In this test, Mega Crop show stronger buffering action than Jacks, and yet, a significant number of people experience just the opposite in their grows.
I cant think of anything - other than bacterial growth - that could account for the PH swings people see with Mega Crop that dont show up with Jacks.
If it was just the alkalinity in someones water, then that would effect Jacks and Mega Crop the same way.
To be fair - its NOT just Mega Crop that has this issue. Ive seen it with Advanced Nutes and Fox Farm nutes. All three of those have organic components. It seems to me it has to be those organics that are the cause. Bacteria, algae, etc eat that stuff and drive the PH up as a result.
I was just reading an article about growing algae in tanks to sequester/trap carbon. They pointed out that as algae eat, they use up carbon dioxide, and convert it into some form of plant matter. That action will drive PH up for sure.
Its the same cycle that occurs with the alkalinity thing - remove C02 (via aeration) and the PH goes up.
One big take away for me is that it looks like organics and hydro just dont mix.
It also makes me wonder about folks using ābeneficial bacteriaā to keep root rot down. Seems to me they are just adding another layer of problems on with PH control.
I think this is a very very important find. Thank you for doing this @Northern_Loki !!!
Linear regressions are based on least squared calculation between ~5.6 to ~<6.5 PH.
Thereās a bunch of things that could differ Iād think:
Organics seem to be a likely culprit for several of the experiences shared across the various threads. I think maybe alkalinity in a couple of other examples (e.g. keeps drifting to ~6.3). And, Iād assume precipitation could also be causing PH shift in some scenarios.
The ammonium ratios will effect the natural PH shift due to plant feeding. Having slightly higher ammonium ratio can have a buffering effect but, unless well planned, it might be akin to skating on the razor of toxicity.
Buffer amendments along with inherent buffers have been discussed in this thread.
Which organics are feeding micro-organisms would be one question. Is it amino-acid based chelates? Or something else in thereā¦
This is fascinating. Thank you for taking the time to do this, and reporting the results in such a clear manner. Much appreciated!
Just saw this part. Thatās a good question.
Is there a difference? Iād think weād be talking aerobic vs anaerobic. Aerobic typically considered fine? PH effect of aerobic bacteria? I donāt really know. Should research this.
