Calcium and Magnesium

[pure_bordem]

While I am asking stupid questions...
 
I know peppers need them some cal and mag, but I never see how much. My fert is a 5-10-10 and has 7% calcium. I picked up some Epsom Salts which says it is about 9% mag. Are these values ok? Should I use more, less?
 
Also when doing mag sprays, should I just sprtiz and let go, no puddles? Should I put it in the soil instead? How often? I see some people do it weekly, others do it every 2 weeks.

 

[96strat]

That will be fine but I would add some blood meal to your water its 12-0-0 for the veg period less k till flowering starts.

 

[queequeg152]

magnesium sulfate(Epsom salt) should be like... 45% 55% magnesium and sulfate. not 9%.

you dont need alot of magnesium OR sulfate... about 1 gram per gallon will give your plants all that they need.
you dont need to spray it. water it in, it will work far better.

 

[Spicy Mushroom]

96Strat I thought bonemeal was 4-12-0 and primarily used as a source for phosphorous? 

 

[Big Kahuna]

That will be fine but I would add some blood meal to your water its 12-0-0 for the veg period less k till flowering starts.

 
 

96Strat I thought bonemeal was 4-12-0 and primarily used as a source for phosphorous? 

 

[Spicy Mushroom]

Oops!
 
Been studying all day for an exam. Mind is getting a bit tired. Doh >.<

 

[Hybrid Mode 01]

magnesium sulfate(Epsom salt) should be like... 45% 55% magnesium and sulfate. not 9%.

 

 
     Epsom salt is MgSO4 heptahydrate, not pure salt.

 

[moruga welder]

96Strat I thought bonemeal was 4-12-0 and primarily used as a source for phosphorous? 

YOU DARE TO QUESTION THE TEACH !!!!     

 

[queequeg152]

Epsom salt is MgSO4 heptahydrate, not pure salt.

yes, very true i forgot about that.

still though, 24 and 34% according to my math.

so the 9% comes from the molar mass of magnesium compared to that of sulfate and 7 moles water.
24/246 or so.

 

[Proud Marine Dad]

magnesium sulfate(Epsom salt) should be like... 45% 55% magnesium and sulfate. not 9%.

you dont need alot of magnesium OR sulfate... about 1 gram per gallon will give your plants all that they need.
you dont need to spray it. water it in, it will work far better.

Put a bunch of good compost in the soil and you won't need anything!

 

[nzchili]

dolomite lime is good to throw into the mix.
it adds cal / mg and also stabalises the Ph

 

[Hawaiianero]

Agricultural Lime is mostly calcium with a little magnesium mixed in.
Cal-mag is a good source of both
Google it

 

[pure_bordem]

Put a bunch of good compost in the soil and you won't need anything!

If only I had the means to make it! Got no where to set a compost up.
 
 

dolomite lime is good to throw into the mix.
it adds cal / mg and also stabalises the Ph

 

Agricultural Lime is mostly calcium with a little magnesium mixed in.
Cal-mag is a good source of both
Google it

 
If I didn't have calcium already in my fert I would probably just rock a cal/mag but I have a hard time finding specialty products in my area so I have to work with what I can find at big box stores and local farm stores. Didn't have time to order anything online. 

 

[Proud Marine Dad]

If only I had the means to make it! Got no where to set a compost up.
 

I feel for you my friend. I am blessed to have enough biomass to make some good compost each season.

 

[Spicy Mushroom]

YOU DARE TO QUESTION THE TEACH !!!!     

 
This is clearly one of those moments I should fall on my sword lol

 

[Hawaiianero]

If I didn't have calcium already in my fert I would probably just rock a cal/mag but I have a hard time finding specialty products in my area so I have to work with what I can find at big box stores and local farm stores. Didn't have time to order anything online. 

Well in that case, Epsom Salt (Magnesium /sulfate). Too little is better than too much. Different plants have different needs. Good luck

 

[pure_bordem]

Well in that case, Epsom Salt (Magnesium /sulfate). Too little is better than too much. Different plants have different needs. Good luck

Thanks. I just found it odd no one recommends a general amount despite peppers loving the stuff.

 

[96strat]

Thanks. I just found it odd no one recommends a general amount despite peppers loving the stuff.

my mag water soluble mag at 10 percent and sulfur so4-s at 13 percent said to put 1/2 teaspoon per gallon of water. My calcium sulfate is 22/18 is 1/2 teaspoon per gallon. Got these from Grow-Biotic in CA number 805-252-7962 go to their site grow-biotic.com. Hope this helps

 

[queequeg152]

Thanks. I just found it odd no one recommends a general amount despite peppers loving the stuff.

2 grams of hydrated epsom salts will meet 100% of your plants needs for both magnesium, and sulfate.
this solution, assuming 100% pure epsom salt, yield approx:

52mg/L and 69mg/l magnesium and sulfur respectively.

note that these are low numbers. you need around 200 mg/l nitrogen and around the same calcium.

generally speaking, magnesium and sulfur are very rarely missing from natural soils that are not agressivly cultivated, this is even more true for phosphate. i think the vast majority of folks are supplementing it for no clear reason, other than to add nitrogen. nitrogen is almost always going to be your limiting nutrient. with that being the case, i suggest you just supplement nitrogen.

you can add nitrogen by means other than calcium magnesium solutions. namely with calcium nitrate, ammonium sulfate, potassium nitrate, ammonium nitrate, sulfur coated urea, polymer coated potassium nitrate, sulfur coated potassium nitrate, and various organic forms of nitrogen.

if you are growing in native soil, id suggest getting a soil test done. they cost little more than your time and effort.

if you are growing in an inert medium with organic amendments, i suggest you defer to established resources in calculating the macronutrient content of various amendments.