PH level

[RandyHunter]

Hi i am a new grower and would like to ask if molasses affects the PH of the soil. thanks in advance.

 

[crucialbunny]

Molasses can lower soil PH. The purpose of using it is to feed microbes as well as beneficial bacteria in your grow medium. It's these little beasties that help break down nutrients in living soil so your plants can more readily absorb them. When everything is working in harmony the microbes will in a short time balance the PH of the soil. I've been growing this way for a few years now and my PH remains consistent throughout most of the grow. Last year toward the end of my grow some very hot days cooked a number of my pots and I was chasing PH issues for a couple weeks.

 

[Rwise]

Welcome to GWE
Yes molasses is acidic.

 

[grouchyoldman]

No pH effect here.

I am adding a tablespoon of unsulfered molasses to each gallon in the last weeks before my current harvest. My town water supply is pH 7.0 out of the tap and doesn't seem to change after adding the molasses.

So the molasses effect on water pH probably depends on the alkalinity which acts as a buffer resisting pH changes. Here's a nice discussion.

https://www.smart-fertilizer.com/articles/pH-alkalinity/

 

[dilvish]

Yes molasses will lower the PH. It really depends on how much you use though. Personally I use nutrients that mix with my water so I can test the PH just once. Since I thoroughly flush my soil or coir approximately every 2nd or 3rd watering, I don't find the need to test the PH of the run off or the soil.

 

[RandyHunter]

Thanks for the info guys. my tap water is ph 7.4 so ill add molasses and see what happens.

 

[Rwise]

I first use lemon juice to kill chloramine/chlorine then 12 hours later the PH has returned to 7.1, then I use molasses to drop it to 6.5 range. In tests it stays there after 12 hours.

 

[OlderNOTwiser]

Rwise How much lemon juice to neutralize the chloramine? I use it as my pH down but it is a few drops at most. Is that all that is needed or is there a larger "shock" dose for the chloramine?

 

[Farmbuck]

Here is my technique: I usually prepare my molasse a few days ahead. I mix one tablespoon per 4 liter of water. A day or two I check the PH and I balance my PH base on if it's up or down. I always try to maintain it between 6.3 - 6.5.

 

[Rwise]

I use 1 lemon or lime to 5 gallons water, juice it and drop the whole thing in, then let it set until the PH rises back to where it was when it came out the tap (about 12 hours). Thats probably to much juice but, the bad shit is dead!

 

[Rwise]

I have read molasses also kills chloramine.

 

[OlderNOTwiser]

I think I can jigger some numbers and make that work in my small grow. I currently need about 3/4 gallon so a few slices and let her soak overnight will work for me. Wifey happens to have some lemon wedges getting wrinkly. I may have a use for them! Thanks, Rwise.

 

[Farmbuck]

Well good to know my friend. Thanks.