I found that my Bloom Nute mix with Molasses went from 6.5 pH to 4.4 pH in one day. It took over 200 pH Up drops/Gallon to restore. This must be fermentation and fermentation creates alcohol. Could this be bad?? Should Moly be added just before feeding??? Thoughts?
Molasses Fermentation
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What pH meter? Calibrated? What is your water source, and its starting pH?
If you really went from 6.5 to 4.4 in one day, that is huge, and intolerable. Just in case you did not know, that is a change by a factor of more than 100x. If your nute mix does that sort of mischief in your planting medium, it could bugger your grow. I do not know if this could be down to the molasses, and will be interested in others' thoughts, but if I were you, I would figure out what is going on before continuing to use the mix.
If you really went from 6.5 to 4.4 in one day, that is huge, and intolerable. Just in case you did not know, that is a change by a factor of more than 100x. If your nute mix does that sort of mischief in your planting medium, it could bugger your grow. I do not know if this could be down to the molasses, and will be interested in others' thoughts, but if I were you, I would figure out what is going on before continuing to use the mix.
Cheap pH meter confirmed by pH chem color test.
City lake water at 7.2 with Miracle Gro Bloom and Molasses was pH'ed Up to 6.5/1200 TDS. 0ne day later down to 4.4. pH'ed Up (again) to 6.5 and found 1 day later it dropped to 6.0. Will test again tomorrow. My guess will be another drop due to continued fermentation. My little science experiment!
FYI - Regardless of my quandary nothing but good news on my Blue Mystics at day 45. I doubt they will need more than 69 days.
FYI 2 - Last year I noticed my run-off pH drop to around 5 after beginning the Molasses. Worrisome but no bad effect noted.
FYI 3 - I brewed beer many years ago and learned fermentation continues until the sugar is depleted or the acid level gets too high for yeast. Just measured a dram of my Michelob Ultra at 4.4. Finished off the bottle and began to contemplate....
City lake water at 7.2 with Miracle Gro Bloom and Molasses was pH'ed Up to 6.5/1200 TDS. 0ne day later down to 4.4. pH'ed Up (again) to 6.5 and found 1 day later it dropped to 6.0. Will test again tomorrow. My guess will be another drop due to continued fermentation. My little science experiment!
FYI - Regardless of my quandary nothing but good news on my Blue Mystics at day 45. I doubt they will need more than 69 days.
FYI 2 - Last year I noticed my run-off pH drop to around 5 after beginning the Molasses. Worrisome but no bad effect noted.
FYI 3 - I brewed beer many years ago and learned fermentation continues until the sugar is depleted or the acid level gets too high for yeast. Just measured a dram of my Michelob Ultra at 4.4. Finished off the bottle and began to contemplate....
Next day stayed at 6.0. Must have depleted the sugar. Going to watch the next gallon closely.
What media/soil? How much molasses are you adding? Why do you add it; for example, do you presume you are feeding beneficial microbes (yet you don't mention adding any)?
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Try your test with Miracle Grow Bloom only... Glad to hear that the plants are happy though.
Rationale for Moly = Flavor enhancement and micro-bio support.
Soil is mixture of store bought potting soil, my garden soil and perlite.
Redid the Nutrient sequence and duplicated past results:
Mix of aged water and MG Bloom had to be significantly pH'ed Up to 6.7/950 TDS
Added 1 tbsp Moly/Gal. which yielded 6.6/1130
Next day pH = 4.7/1110
2nd Day pH = 4.4/1105
pH'ed up (a lot!) to 6.5/1155 and container run-off was about 5.3/1275 which has been typical.
I will try the 2 day sequence with MG Bloom no Moly mixture. At day of use, add Moly, remeasure and test run-off.
Plants are still thriving at day 51. Weather has been good. Packing on the buds!
Still thinking on the significance. Can't imagine that an unexpected 4.4 pH could be good. Recommendation could be always add your Moly and pH adjust just at time of use.
Soil is mixture of store bought potting soil, my garden soil and perlite.
Redid the Nutrient sequence and duplicated past results:
Mix of aged water and MG Bloom had to be significantly pH'ed Up to 6.7/950 TDS
Added 1 tbsp Moly/Gal. which yielded 6.6/1130
Next day pH = 4.7/1110
2nd Day pH = 4.4/1105
pH'ed up (a lot!) to 6.5/1155 and container run-off was about 5.3/1275 which has been typical.
I will try the 2 day sequence with MG Bloom no Moly mixture. At day of use, add Moly, remeasure and test run-off.
Plants are still thriving at day 51. Weather has been good. Packing on the buds!
Still thinking on the significance. Can't imagine that an unexpected 4.4 pH could be good. Recommendation could be always add your Moly and pH adjust just at time of use.
Final Report:
1. Miracle Gro Bloom mixture is stable over time
2. Molasses mixed with MG Bloom causes almost no pH change at time of mixing
3. Molasses fermentation can begin immediately and progress over time. At day 2, pH can drop from 6.5 to 4.4.
Recommendation:
Either use your Bloom Nute with Molasses immediately or re-adjust with pH Up just before use. This to avoid an inadvertent extremely low pH feeding caused by Molasses fermentation. This is likely to be true for other Bloom fertilizer blends.
1. Miracle Gro Bloom mixture is stable over time
2. Molasses mixed with MG Bloom causes almost no pH change at time of mixing
3. Molasses fermentation can begin immediately and progress over time. At day 2, pH can drop from 6.5 to 4.4.
Recommendation:
Either use your Bloom Nute with Molasses immediately or re-adjust with pH Up just before use. This to avoid an inadvertent extremely low pH feeding caused by Molasses fermentation. This is likely to be true for other Bloom fertilizer blends.
What's happening in the reservoir - who cares? What is important is what's happening in the soil/medium. Have you tested soil pH and run-off with and without molasses? I would presume the same fermentation, maybe even more intense, would happen in living soil compared to in the reservoir, so there still may be in-soil low pH problems in your setup.
With 1 tablespoon of molasses having ~20 grams of various sugar, adding 20 grams of sugars/gallon (5.3 g/L) seems very extreme (plus does your bloom feed already contain some carbs?). Remember the Krebs Cycle from biology/science courses? Aerobic metabolism generally converts sugars into citric, lactic, malic, fumaric, succinic, glutaric, ascetic, etc. acids (and acetates). So lower pH should be expected from molasses fermentation.
I've never figured out how so many report good results using such high amounts of molasses. I now use it with most every feed, but at most at 1-2 grams/gallon.
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