Ok, my setup isnt nearly as precise or accurate as @Northern_Loki , but I mixed up a sample of Mega Crop in my RO water. Nothing else added.
The EC is 1.7 ±. Im using a BlueLab truncheon meter, so its plus or minus .05. The PH settled at 5.3 within a minute or two and has stayed there for the last hour. I will check it periodically while this experiment continues. I can add other things if it seems appropriate as we go forward.
List is in the OP. Focus, at the moment, is on figuring out the buffering. I am waiting to start item (2) until I get a pipette and some KOH that I had ordered. Item (2) is titrating the MC with a base (which may be the KOH).
Practicing a bit before I start some sampling for the record, the following is a preview of what a MES buffer could do:
Baseline feel. To get an idea of what the initial solution does in a beaker before I start mucking with it. And, to see how much PH drift is occurring (since that has been noted as occurring).
Just experience really. Potassium silicate is extremely alkaline, and every time I mix it, I have to use a lot of pH down to normalize the pH. So it might balance out well with MC, being very acidic.
I found a diy magnetic stir plate on YouTube. Dude used a 120mm PC fan, 12v power supply, bolts, washers, rubber washers and neodymium magnets and super glue and an old cigar box.
Mounted the fan inside the cigar box and glued a washer to the center. Stuck magnets to the washer.
Pretty simple and cheap. Used it for yeast cultivation for home brewing.
Put an Erlenmeyer flask with a Teflon coated magnetic stir bar inside and it worked quite well
Yes, I’m thinking PH primarily but will not rule out MES (thanks).
Starting to see some precipitation a bit over 7.5 at ~66F. I’ll need to drop the PH back down to see if this remain insoluble and perhaps verify against a different PH adjust reagent.
I’m still getting set-up and this has MES in it as well. But for edification:
PH ~= 7.6
PH ~= 8.6
PH ~= 9
PH ~= 9.4
Final, settled percipitants:
To see percipitation at ~7.5 (or lower) seems a bit low.
Edit: Appears reversible, precipitant is soluble (when using GH up/down), back down to PH 6:
One step at a time… One step at a time… 
Awesome, looking forward to seeing what you observe. We can tune what we look at if some oddities arise.
I dunno if it helps much but northeast UK my ph is normally high 7s but with megacrop at EC 1.4 when I mix a batch up it sits at 6.4. It raises to round 6.8 over 24 hours it. I’ll check tomorrow the ph. May be just needs time to settle.
Thanks, good bullet point.
There does seems to be some amount of “slow” drift in the controlled solution (beaker) but I have not monitored it over 24 hours. About 0.1PH up over a ten hour period in this case (with RO).
Larry has also seen some drift, as well, but I think that was mainly occurring within his system. And, it was significant. I think he’s drain to waste so it’s not plant uptake. He is trying a control to see how it behaves comparatively.
Thinking is, first eliminate some of the variables due to a live system and to narrow down the behavior of Megacrop. And, to see if we can reliably and safely add a buffer to help mitigate PH drift in actual use. Don’t know, may find something useful or maybe not.
Any data points or insights to consider is good.
I still have a nutrient mix bubbling away. I’ll test it tomorrow and see if it’s raised again. I know its not exact science but being somewhere near the sweet spot for nutrient uptake has to be a good thing
Update on my RO + Mega Crop sample. Its been about 24 hours and the PH has gone from 5.3 to 5.6.
BUT - when I took a close look under bright lights, I noticed what looked like some particles suspended in the solution. There was nothing built up on the bottom, and no scum on top, so this stuff is just suspended in the solution.
BUT #2 - there was also one longish hair and what may be a very small bug of some sort also floating in the solution… 
My grow room must not be very sterile
I dont know if the cloudiness is due to some precipitate or contamination. This is the first time I have seen anything like this with Mega Crop.
So, I just drew some fresh RO and am starting over - keeping the lid on this time. Im going to keep this sample just to see what it does over time.
Edit: Got the new sample mixed up. PH is 5.3 again, and the solution is crystal clear - zero particulates visible.
Edit #2 - the cloudiness I was seeing is nothing like what @Northern_Loki showed above. I had to look closely to see anything.
So, just to keep this clear in my mind - the sample that showed the cloudiness had MES in it?
What was the PH before/after adding the MES?
Im assuming you added PH Up to raise the PH in that sample? Had it already had PH up and down added to it - like the control sample?
Correct. I have not yet “officially” started a titration on plain MC (step 2). The MES plot (and associated photos) that I had posted was just getting a procedure figured out. Whether the MES has anything to do with the precipitation should be answered shortly, if that’s what you’re wondering about. But the curves might be of interest.
Correct. GH PH up. The MC makes for a relatively acidic solution, so to plot the buffering, simply drop by drop PH up. Initial solution was MC + MES to start and then PH up for the plot. Wasn’t planning to go more acidic than the starting PH of solute.
I then later adjusted the solution back down (with PH down) to test if the precipitate was soluble or insoluble. The precipitate remained soluble when adjusting back down (when using the GH up) .
Now, whether using GH up/down is the right thing to graph a titration plot is a different question. Weak acid + weak base? Potassium carbonate as the base?
No it did not, just MC and MES.
Yes, note that I only started paying attention around 7.5 PH as it started to become obvious. May have been started earlier in the curve.
Edit: I left the solution stiring over night (last photo in post #25) after having re-dissolved the precipitants at PH6. Solution PH went up a couple of tenths and I am seeing a small amount precipitant again.
For sure. Did you get any curves for this initial trial? Im really curious to see how the MES effects the PH swings.
I hope you are not asking me about that Thats still a major source of confusion for me. 
Arent GH PH Up and Down both strong acid/base?
Post #22 in this thread has an example plot.
Don’t “really” know what’s in there. One version of the SDS lists Potassium Carbonate + Silicic acid + inerts for the PH up. Another version lists just the Carbonate. Potassium carbonate is considered a weak base (or moderately so) from the reference I looked at. It is strongly alkaline and will also act as buffer.
Phosphoric acid is also considered a weak acid. The SDS for the GH PH down lists Phosphoric acid + Citric acid. While another version also includes Mono-ammonium phosphate. A bunch of possible buffering complexes.
Weak / strong is in the context of chemistry definitions where a strong acid completely disassociates in water or nearly so. A weak acid, conversely, does not fully disassociate.
So, debating whether to go with a strong base when titrating or just keep on with GH to capture the buffering regions.
Edit: oh, and looks like they’ve just modified the formulation. “More stable for mixing and storage and more under the hood changes”. Leaves it open for interpretation?
Been following along here and there one thing cloudiness could can result from is bacteria/ wild yeast and such getting into the samples it would be very difficult to totally eliminate them, and since we’re dealing with nutrients in essence your more than likely just propagating them over time by feeding them, would be interesting if ya had a microscope to validate if this could be going on and if so all the “bugs” could also alter PH in a nice nutrient solution.
My US $0.02
Megacrop 1.0 had humics on it, caused clogged sprayers and precipitation. Also suspected to contribute to mc slime…
From the previous experiments in the MC thread, brown fluffy stuff did look like organic material.
Looks like they still have kelp in the in the 2.0 version. Is the kelp the source of the humates you are thinking of?
Edit: Appears they have removed the chitosan and the cellulase enzymes.
Havent read all the new posts, in a rush, so just a quick up-date.
The new sample I made is still at 5.3. It flickers up to 5.4 when I stir the solution, b ut drops back to 5.3, so maybe somewhere in between. So, basically no change in the last 15 hours or so since I mixed it up. Also, still zero sign of precipitation of any kind.
The old (contaminated) sample is still slightly cloudy and its PH is still reading 5.6.
Both are EC 1.7.
On the precipitation observation:
I left the solution stiring over night (the last photo in post #25) after having re-dissolved the precipitants by bringing it back down to PH6. Solution PH went up a couple of tenths to around 6.3 and I am seeing a small amount precipitant again. Grain of salt, though. Lots of up/down added.
