Agriculture Reference
In-Depth Information
Oyster shell
products are uniquely capable of a few excellent contributions to a living soil mix. Cannabis
loves calcium, and microbial life needs and loves calcium as well. Oyster shell products provide slow-re-
lease calcium, and that's the first benefit, but wait, there's more—when building soil mixes you always
want to be somewhat aware of the ratio of calcium to magnesium, which should be around 5:1 respect-
ively. Oyster shell products essentially provide a pure calcium carbonate which breaks down very slowly,
releasingcalciumforthemicrobiallife,andhencetheplants,touse.Ifyourmagnesiumlevelsgettoohigh,
bad things start to happen, and sothis can be a tricky dance, due to the fact that cannabis also loves a lot of
magnesium. Dolomite lime (see below) brings in magnesium along with calcium, and I use this in my mix
as well.
I use two grades of oyster shell products, the ground and crushed versions. The crushed is just larger
pieces than the ground, which has a sand-like consistency, and the main difference here is the length and
the strength of the buffering effects the calcium carbonate has on the soil mix. This is another benefit of
using these shells. I like using the ground shells (also known as oyster shell flour) as a buffer for spike and
layer mixes using things like guanos and blood meal in them. If not for the buffering effects of the ground
oystershell,thoseproductswouldreallytakethepHdowntoolowforatime.Inaddition,calciumisoneof
the most underrated nutrients ever in cannabis growing, because cannabis loves slowly released sources of
calcium, and I even use crushed oyster shells in my worm farm food (kitchen scraps and leftover cannabis
matter with shredded junk mail) to make sure my castings are calcium rich. I advise you to keep calcium
on your mind when customizing soil mixes and you will be one happy camper!
Both crushed (right) and ground (left) oyster shells are fantastic additions to a living soil mix
You can see that I use plenty of the crushed shells globally in the 2.1 soil mix, and this is because I like
the larger pieces for their artificial reef qualities, and for the length of time it takes them to break down.
Elements in a living TLO mix tend to break down much faster than is stated in many organic grow topics.
My crushed shells last about 90 days, from what I can see.
Dolomite Lime
isreallyimportantforyoutounderstand,whengrowingincontainersespecially.Itismade
from both calcium and magnesium, and cannabis plants love plenty of both of these elements. There are
many kinds of lime, so be careful here. Using hydrated lime, for example, could very easily become a dis-
asterinalivingsoilmix.Dolomitelimeiswhatyouwanthere,andIusethisasoneofmyonlymagnesium
