Has anyone heard of Gypsum (hydrated calcium sulfate)

[JohnN]

Has anyone heard of Gypsum (hydrated calcium sulfate) for lower the pH in soil? I'm growing in Virginia. My plants are Diesel Elvis #5 and Crack Weed. The soil is regular potting soil but I amended it with perlite, vermiculite and sphaghum moss. The nukes I use are Jacks Classic All Purpose 20-20-20, SuperNova 1-1-1, Black strap molasses, Peruvian seabird guano 10-10-2 and Alaska Fish Fertiziler (5-1-1), I recently stop using the fish fertiziler because my girls are getting slightly digged up by animals. I think the fish fertiziler is attracting them to the plants. I am going to buy seaweed at the end of this week and start using that also. Some of my girls are 6 feet tall and others are 5 feet tall. Others are only 3 feet tall but they are in desperate need of transplanting which is slowing them down. I am in the midst of moving them again due to security issues so it's really hairy now because they are so big. When things are settled and they are transplanted, I am going to take a pH reading. If the pH is too high, which I don't think so now, I wanted to know if anyone has heard of Gypsum (hydrated calcium sulfate) for lowering the pH levels? I want to buy something and keep it around in case I need it. I read about this in Jorge Cervantes' book Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible. Any help would be greatly appreciated. Thanks.

 

[Sublime]

Gypsum is used in regular gardens, especially for tomatoes. When I had a problem with blossom end rot in my tomatoes, gypsum was recommended over garden lime as an ammendment because it provides calcium but without raising the ph like garden lime does. Gypsum seems to be a common ingredient in many mixes as well, but I don't know that much about it for mj, as I grow indoors with hydroponics... :smiley_joint:

 

[ismokepot]

I know gypsum is recommended to break up clay soil......... but haven't heard about it being used specifically for pot growing.

 

[billopuffalot]

yer
down here in oz gypsum is a clay breaker
i think for ph and soil
the dolomite lime is the go
all the best
bil

 

[BigSatan]

sheetrocks made of gypsom

 

[JohnN]

Thanks. I will stick with dolomite lime.

 

[Chemotype]

Gypsum (calcium sulfate) can improve the physical condition of many types of soils. The more soluble gypsum products provide enough electrolytes (cations and anions) to promote bonding of tiny soil particles and inhibit the dispersion of aggregates, which are where all your nutes become available to the plant, thus this will prevent surface crusting. Field trials show that gypsum treated soils permit greater water infiltration and reduce the strength of hard subsurface layers allowing greater root penetration for water uptake. It can also reduce unwanted salts in the soil.

One reason for the effectiveness of gypsum is that calcium from surface-applied gypsum moves down the soil profile more readily than that of lime. As lime dissolves, its reactions raise the pH, increasing the pH-dependant charges on the soil colloids, which retain the release of Ca2+, preventing its downward leaching.

Gypsum works great indoors or out. And it will not increase pH.

Use gypsum in your soil. It's far better than lime.

To lower the pH of the soil you should use pineneedles, pine sawdust, acid peat moss, for organic applications and if thats not enough use Ferrous sulfate or elemental sulfur.