Jack's 3-2-1/Master Blend...replace calcium nitrate with calcium sulfate during flower?

I know a few growers who have been using the Jack's 3-2-1 system or Master Blend's system and love them....but the problem is that these systems call for Calcium Nitrate. The idea during flower, is to minimize the nitrogen but maintain the calcium. So, if the Calcium Nitrate is replaced with Calcium Sulfate, then this can be achieved....right? Also, the additional sulfur might be of benefit, as well....?

Has anyone tried this?

Also....What about Calcium Phosphate?

Calcium acetate is fairly cheap too.....about $25 a kilo at bulk supplements....adds nothing but readily available calcium

They have an amazon store too. Its what i use when i just want to add calcium.

Calimagic from GH has very low nitrate content, it uses some other form of Ca along with a little CaNO3 and MgNO3. If you havent tried just dropping the CaNO3, try that one run.

You still need nitrogen in flower, completely swaping the calcium nitrate for calcium sulfate you probably wouldn't want to do until the last 2-3 weeks

nxsov180db said:

You still need nitrogen in flower, completely swaping the calcium nitrate for calcium sulfate you probably wouldn't want to do until the last 2-3 weeks

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Yes, I agree. Both Jacks Part A and Master Blend Part A have low amounts of Nitrogen in and of themselves, but they both also require Calcium Nitrate for the complete formula. However, adding all that extra Calcium Nitrate is too much nitrogen for flower.

And yes, I would only do this during later in flower.

Calcium binds to phosphorous so using something like Master Blend alone could cause a lockout. You could also just scale back the MB/Calcium Nitrate in equal amounts.

If you are not using tap/well water why not just use it and jacks without CaNO3. People have used heads 6/9 in coco for a long time. Alot of them cut the floramicro at the halfway mark and did fine. Thats no Ca for second half of flowering. I always went with micro longer but thats still the last 3 weeks without Ca. I never noticed a Ca deficiency in mine or theirs. Just something to think about.

You can use calcium sulfate (gypsum) to supply all calcium requirements a plant needs. But some nitrogen is still required in flower so just replacing half (based on Ca weight) the CaNO3 with CaSO4 is likely better.
The problem is that CaSO4 is borderline insoluble so it will take some time to dissolve.

The added sulfur doesn't harm the plant but will likely do no good. With Epsom salt as magnesium source you should have sufficient sulfur levels already.
Calcium phosphate is not suitable as it is insoluble. That is the stuff that forms if you mix concentrated solutions of two part fertilizers.

Calcium acetate or any organic salt (organic meaning containing carbon) is ill advised. The acetate fuels bacteria grow which clogs all hoses and more. You also get pH swings and after all acetate is metabolized the product left in solution is either calcium carbonate (insoluble) or the calcium salt of the acid you used to control the pH.

Calcium nitrate and calcium acetate are both created by use of an acid. Both start off as calcium carbonate. So not sure how one increases bacteria growth and one does not.

Is there a way of using part A and calmag alone in conjunction?

ShowMeDaBudz said:

Calcium nitrate and calcium acetate are both created by use of an acid. Both start off as calcium carbonate. So not sure how one increases bacteria growth and one does not.

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Bacteria (or fungi) need water and "food" to grow. That food is one minerals (which are plenty as you have everything a plant needs) and two some source of chemical energy. That could be sugar, some plant tissue or acetate in this example.

Think about it. Have you ever seen moldy rock? Or tarmac with a layer of slime? But bread, leaf litter etc. are usually moldy if they are wet enough.

Tolerance Break said:

Is there a way of using part A and calmag alone in conjunction?

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Cal Mag is usually calcium nitrate and magnesium nitrate and some iron compounds. If you use that instead of the usual magnesium sulfate to supply magnesium it might be a bit high in nitrogen and low in sulfur compared to the usual recipes.
I don't know how much sulfur is in that part A and if that would be sufficient.

Jacks already came out with a new 0 nitrogen part A formula (masterblend is copying them as well), so you have more control in flower now. You still use calnit though, but able to control the overall amount of nitrogen by having 2 different part A's to mess with, instead of altering the amount of part B and throwing off ratios, etc.. Making it more like a 3 part line.

Tolerance Break said:

Is there a way of using part A and calmag alone in conjunction?

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I suppose so, but I'm already using Epsom salt, so the magnesium is taken care of.

tstick said:

I suppose so, but I'm already using Epsom salt, so the magnesium is taken care of.

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All good, I was asking for myself. I was thinking about how to use less nitrogen in the last few weeks of flower, and using jacks part A or finish with calmage came to mind

Tolerance Break said:

All good, I was asking for myself. I was thinking about how to use less nitrogen in the last few weeks of flower, and using jacks part A or finish with calmage came to mind

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calcium chloride is what ppl are doing the last couple weeks if you don't want to wait all day to dissolve calcium sulfate

Tolerance Break said:

All good, I was asking for myself. I was thinking about how to use less nitrogen in the last few weeks of flower, and using jacks part A or finish with calmage came to mind

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Get a small aquarium "wave maker" pump (costs 30-40 bucks new, less if used). Then you can dissolve gypsum in just a few hours and fulfill your calcium needs. Micronized qualities are also available specially fot agriculture. They dissolve a bit quicker.

Lou66 said:

Get a small aquarium "wave maker" pump (costs 30-40 bucks new, less if used). Then you can dissolve gypsum in just a few hours and fulfill your calcium needs. Micronized qualities are also available specially fot agriculture. They dissolve a bit quicker.

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Thank you!

So, in theory, I could replace part B with gypsum, while still using Epsom?

Tolerance Break said:

Thank you!

So, in theory, I could replace part B with gypsum, while still using Epsom?

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Gypsum for Calcium and Epsom for magnesium. It's difficult to have sulfur toxicity.

But you should still have some nitrogen available. It's still an essential nutrient.

Lou66 said:

Gypsum for Calcium and Epsom for magnesium. It's difficult to have sulfur toxicity.

But you should still have some nitrogen available. It's still an essential nutrient.

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I believe part A has a bit. I've seen some people experimenting with ratios to replace Part B and sub calcium.

Chemistry is not my strong suit, so it's a struggle. When I'm done with electrician school, I hope to tackle chemistry as it relates to plants