Cal mag additive in recycled soil?

KLITE

Well-Known Member

• Feb 25, 2015

• #1

Hi all

Epsom salts are dear as fuck at pharmacy here and my online order is late. Would you use a cal mag additive from growshop to correct a deficiency if you planned to re use that soil a few more countless times?

Thanks

 

rikdabrick

Well-Known Member

• Feb 25, 2015

• #2

You can use dolomite lime and it's cheap from ag stores. I use a 50/50 mix of dolomite and gypsum in soil I reuse constantly and I think it works pretty good. I think about once a month is a good time for re-ammending with it.

 

hyroot

Well-Known Member

• Feb 25, 2015

• #3

dole lime and gypsum take a long time to break down. Crab meal and neem meal have cal and mag. Rock.dust has trace amounts of both. Kelp meal has cal. Just brew a tea of any of those. Keep in mind too much cal will lock out mag and vice versa.

edit:

I forgot about oyster shell flour. That has both too and is soluble.

 

Last edited: Feb 25, 2015

J

jstone1633

Well-Known Member

• Feb 25, 2015

• #4

Dolomite has the wrong magnesium/calcium ratio. It could bind up your soil. Oyster shell flour and aragonite flour are pure forms of calcium carbonate...much better sources. Hi-cal agriculture lime also a nice choice. I personally use 1/2 cup aragonite flour and 1/2 cup of gypsum in my no til garden and don't see much problems. I also use crab shell, rock dust, kelp, and neem as hyroot mentions but not necessarily for their calcium content.

 

greasemonkeymann

Well-Known Member

• Feb 25, 2015

• #5

KLITE said:

Hi all

Epsom salts are dear as fuck at pharmacy here and my online order is late. Would you use a cal mag additive from growshop to correct a deficiency if you planned to re use that soil a few more countless times?

Thanks

Click to expand...

A light BSM tea will provide both of those micros as well.

 

May11th

Well-Known Member

• Feb 26, 2015

• #6

I use 1/ 2 cup of dolomite lime per 7 gallons, with 1 cup of oyster shell per 7 gals, or 1 cf of soil.