pH adjustment w/acid

I need to lower the pH of my well water. Is there anything wrong with using drops of muriatic acid to adjust pH? I use this in my pool and have it on hand but don’t know if it safe for my plants.


Oooh, never use muriatic acid for your plant you gone a run right in a wall and kill your babies. :scream: :skull:

Use that instead or lemon juice and always diluted in water, never drop by drop in to your medium…

Hope that you’ll find this useful :innocent::v:@Erniex


Yes, its safe, but very strong. Please use caution while using strong acids as pH down, in growing situations. (Think-Safety-First!)

Phosphoric acid is normally uses as pH down in fish tanks and hydroponic situations as @Niala posted, as its weaker and safer.

I use Muriatic Acid in my aquaponic system. A good alternative is getting yourself an RO filter. Its always best to start off with the proper filtered water than to chemically change it.

Hope this helps, cheers :slight_smile:

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I did not know that you can use safely muriatic acid , my mistake @Aquaponic_Dumme, can it be use in soil as well ?


No worries, that’s why we’re here… :slight_smile:

Muriatic Acid is an old fashioned way to say Hydrochloric Acid. Hydrochloric Acid is gas hydrogen chloride in water. When you dilute it into say ‘well water’, with higher pH, poison gases are released, and it takes time for all the extra chorine and hydrogen to evaporate. Boiling via airstone will speed up this process.

After mixed with water, and left to stabilize, yes, you can use it to water your soil.


Thanks for the info @Aquaponic_Dumme I have give a quick thinking about switching for it but will stick with phosphoric acid :smiley::innocent: Thanks again :v:

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Thanks for the responses and info. I am well aware of the cautions necessary when using strong acids as I have been dealing with my pool and muriatic acid for many years. I ordered some GH pH Down but could be over a week to arrive. Just looking for something for the meantime.

Thanks again for the input and Good Growing to all.:ghost:


Lemon concentrate juice is a good option too, for an immidiate use :wink::innocent::ok_hand:

Just dilute some in a cup with water in a coffee cup. Then use the diluted solution to adjust ph. my ph down is 29%phosphoric acid

I have used aquarium pH up or down. Easy to adjust. Drop by drop. Once diluted, leave open overnight and pour. Check outflow pH. And do it slowly. :sunglasses:

Lots of good suggestions. You guys are great: :+1:

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Bought a pH pen and some distilled water to calibrate. Went through the calibration with pH 4.01 & 6.86 buffer powder mixed with the appropriate amount of distilled water. The pH with both solutions settled within 0.01 of the solution numbers. I then thought I’d test it on the distilled water. I got a reading of ~6.0 for the plain distilled water. Isn’t the distilled water supposed to have a pH of 7.0? I again tested the distilled water with a pH test kit with color strip and got the same value. Should this be a concern since both of the buffer solutions measured correctly with the pen?


Youre ok.

Often, distilled water tends has a lower pH while it’s open to the air, as it absorbs gases. Distilled water is not “pure water”. It can have a pH as low as 5.5pH.

Hope this helps, cheers :slight_smile:

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Or, like the hydro shop near me who sales ph’d distil water, just verify your bottle specs to be sure :wink::innocent::v:

Thanks for the quick responses. So as long as the calibration solutions are giving me the prescribed numbers, I can consider my pen readings to be correct regardless of the raw distilled water readings?:grinning: