Hi, Ivan! Welcome to ATP.
If you mean the commercial product "HTH pH Minus", that is sold for the purpose of adjusting pH in swimming pools.
If you use it in irrigation water or for sprinkling on garden soil, be aware that you're adding some sodium (a salt). Maybe you would never add enough of this to soil that the sodium would "salt up" your garden bed, or make the soil saline.
I guess it is less concentrated than pure sulfuric acid would be, but I suggest that you test the amount that you might use on some small spot first, to be sure you don;t acid-burn and salt-kill anything. That pool chemical might be very concentrated and fast-acting! (Too much would burn plant roots and make the soil TOO acid = pH too low)
the commercial product "HTH pH Minus":
93% SULFURIC ACID, MONOSODIUM SALT (Na H SO4)
7% SULFURIC ACID, DISODIUM SALT (Na2 SO4)
>> Does any one know where I can plant P.H.minus
I don't understand "where" or "plant". Did you mean "how should I use it?"
I personally wouldn't use a pool chemical in the garden if i could find an alternative, like agricultural sulfur. that acts very slowly and is less likely to damage plants, doesn't have contaminants that might hurt your garden, and has no sodium (salt).
