How to get my pH levels down?

Question from a fellow grower:

Hello I am having a problem. I am trying to lower the ph in the soil? I’ve tried mixing lime stone with water then soaking the soil but it doesn’t seem to be working? Also I am told that there is fertilizer for growing and one for the budding?

The easiest way to correct ph is with ph up and down solutions.

For your second question. Most nutrient lines have a 2 or 3 part base nutrient that you adjust according to the stage your plant is in. Most of the well known manufacturers offer a feeding chart that tells you how much you need of each nutrient at each stage.


Lol limestone is alkaline meaning it will raise the pH. Not the ingredient to add if you want to lower pH. Think lemon juice. Get some pH up/down for plants. Or mix ur soil from the beginning. Soil additives take time anyway. Ask @garrigan62 for his soil recipe. He’s a super soil expert

I use old coffee grounds from beans I have ground myself, lightly mixed in with the soil and my last crop was fabulous. :man_farmer:

Really? Coffe grounds? How much? I never thought of this but i put them in my compost for my outdoor veggie garden. I would think it might be to acidic if not composted.

My question is how are you measuring the PH of the soil? If you are doing a slurry test with a calibrated digital meter then you have good data. If you are using a soil probe meter it’s a waste of time as they are too inaccurate for growing well. In fact, bad data is worse than no data IMO.

how are you measuring the PH of the soil? are you using your own compost/soil ?..:santa:

Changing Soil pH, Soil pH Adjustment, Lowering Soil pH


Coffee grounds have a pH around 6.8, close to neutral, so they won’t do much to lower pH . They do add a little nitrogen, so they can help reduce pH over time, just like manure or compost. If you need to drop soil pH more quickly, try watering your plants with leftover (cold) coffee , diluted 50-50 with water.

1 Like

I measure soil by making a slurry and testing with a ph pen and I also test the ph/ppm of water/ nutes going into my plants and the runoff. I had big time issues this last griw with ph and nute burn so im starting to plan ahead now about what soul to use. I have been using happy frog and added some compost which i thought would be beneficial but had the nute burn so I’m thinking about trying somthing new.
Did you notice any taste or smell difference whe growing in the coffee?

not at all, I am smoking some now (its 4.55pm here) puff puff…nope, it tastes/smells like good pot…in my humble opinion we are presented with a massive selection of Nutes without totally understanding their roll in the production of herb.
Companion planting is also excellent and fun.
read this from Robert Bergman…one of the best explanations going .


Very good info, and i couldnt agree with you more about the nutes. Always learning!!

Easiest way to lower ph… adjust water to 5.8. keep watering to runoff and check ph. when runoff is within range (6.5) you are good. sometimes you will need to use 5 or 10 gallons of plain ph 5.8 water before you get what you want. in the future, check the ph of the water AFTER you add all the nutes you want

You say you have a Compost heap outside…there is your ganga soil for sure, but do a pH test methodically on different samples of the soil you want to use…my rule of thumb is as follows…if my compost has lots of worms in it , then I have made perfect ganga soil. :seedling::rainbow::droplet::bouquet:
ps : I seperate out all of the worms (they have a job to do in the compost heap :mage:)


Actually, ordinary household vinegar works great for lowering pH. It just takes a little bit, is totally organic, and plants love it.

I’m growing 3 plants in soil. After adding nutes, I pH the rainwater I use which before adjusting is very acidic…like around ph4…to around 6.3- 6.4 with vinager but the run off ends up close to 7. I’d like to bring it down a bit so in between feedings I give plain water ph’d to around 6.4 and the runoff is pretty close to that. Don’t understand why.I get such a high runoff after feeding. BTW, plants look fine.

do you mix the vinegar in with water ?

Sorry, that’s a mistake. I use baking soda to bring the pH up to around 6.3-4. If I use too much, I use vinegar to bring it back down

@James68 i used white vinegar mixed into the water to bring ph down with great results plus they say that store bought down and up can kill beneficial microbes. I like to stay :100: organic as possible.


what do you use to measure your pH…I am lost with the selection out there…I have been using the colour chart ph tester…but its quite basic.

Get a good digital pH tester, it’s worth the investment. The probes from the garden stores are crap, stay away from them.

thank you for your good advice,would a budget of over 3 figures be about right to get a good pH tester ?