"Could i use some dolomite lime on the final rinse as they both contain calcium and magnesium.I have epsom salts here but dont know where i
would find calcium nitrate in Auckland new zealand."

If you can lay your hands on some nitric acid (almost any chemistry lab will have it) and pour a little (say half an ounce) it on an abundance of dolomitic limestone (say a cup full) in a plastic bucket, it will froth and neutralize very quiclky (seconds to a minute). Then fill the bucket with water, let the remaining limestone settle, and the clear water will now be charged with calcium nitrate ions and if the acid were fairly strong also with magnesium nitrate ions. Use the water.

Be careful. Have water running so that you can wash any spills instantly with a flood of water.

Hi Laidbackdood: Cation exchange is the interchange, or the switching, between cations that are in SOLUTION and the cations that are on the surface of any negatively charged material such as clay or organic matter, in this case the CHC's. Dolomite cannot be used for cation exchange because dolomite is not water soluble, therefore the magnesium and calcium in dolomite are not in SOLUTION, and because they are not in solution they are not in the ionic form, and therefore cannot exchange with the sodium and potassium cations on the negitively charged CHC. Calcium when combined with Nitrate, such as in Calcium Nitrate and Magnesium when combined with SO4 are water soluble forms of Calcium and Magnesium, therefore are ionic (Cations+) when in SOLUTION, and therefore will work in cation ion exchanges. Note, that after twice rinsing CHC's in just a water solution, approximately 2/3 of the salts (Na+ & K+) could still be held by the CHC's. It is the final rinse in Calcium Nitrate and Magnesium Sufate (Epsom Salts) that releases the salts through cation exchange. Calcium Nitrate and Epson Salts should be easily found at suppliers that sell to the greenhouse trade, or at larger nurseries. I purchase both in 50-lb. bags, from a greenhouse supplier in Denver. If members cannot find these in their area I wold be happy to supply a pound of each at my cost plus the postage. Look in the yellow pages under fertilizer or greenhouse suppliers. - Millet

sorry.i thought it was calcium nitrate and magnesium suplhate that was
used for the cation exchange? The magnesium sulphate being the epsom salts side of things.Its the calcium nitrate i cant seem to find.I will persue my quest in auckland.is this correct?cheers

Laidback: Sorry I must have KNO3 on the brain. I corrected my post. It should read Calcium Nitrate & Magnesium Sulfate (Epson Salts). - Millet

OK, I repotted most of my trees today & added more CHC. I noticed when i UN potted, there was a mass of soil too wet around the roots causing possible root rot. Not enough airation & soil was too compacted. Thanks Millet for bringing this to my attention.
Patty

Forgot to say, I did the last soaking of the added CHC in epsom salt &
liquid iron & fert. since they are sprouting new shoots.

You mentioned adding dolomite lime. First time I heard anyone adding lime to citrus. I have some pelletized lime. Should I be adding some?
Patty

Patty, there are many types of lime, most of them I would NOT add to citrus. Dolomite does not change the pH and it supplies calcium and magnesium. Unless you know that the type of lime you have is OK I would not add it. Millet

I brought the bag of lime in from storage shed. It says,
Calcium (ca) .... 35%
Magnesium(mg).. .6%
Calcium Carbonate Equiv. 90%
Equivalent Oxides
Calcium Oxide (CaO) 49%
Magnesium Oxide(MgO) 1%
Calcium Carbonate(CaCO3) 87.5%
Magnesium Carbonate (MgCO3) 2%

Says it helps improve fertilizer availability on acid soils.
So, maybe I will give my plants a sprinkle huh?
The only thing I ever used it on is my figgies in spring. Thanks

Now I'm really confused. I bought "dolomitic lime," which, in the first Google reference I found, was synonymous with dolomite. It is a combination of CaCO3 and MgCO3, as I recall. SB

Stressbaby don't be confused. What you googled is dolomite and what Patty has is dolomite. Dolomite {CaMg(CO3)2} is Calcium Magnesium Carbonate otherwise known as "Dolomite" which basicly is Calcium Carbonate that contains "contaminates" of magnesium. - Millet

I'm a little confused also. Nowhere does it say (on my bag) that it's "dolomite" lime. Is that a brand name? My brand name is Ampel GrowPower & it says it's "pelletized" lime. Looks like small granuals.
Thanks.
I did add some, ...see if it does anything good

No Dolomite is not a brand name, it is the actual name of the chemical compound. Ampel GrowPower IS ONLY a brand name that could be used on any of a millon products dreamed up by manufactures. With the use of products like calcium or manesium , or the combined form (dolomite), you should not see anything. You would only see the tree's deficiency damage when they are not present in the tree's tissues. - Millet

[quote from Gonebananas]
"If you can lay your hands on some nitric acid (almost any chemistry lab will have it) and pour a little (say half an ounce) it on an abundance of dolomitic limestone (say a cup full) in a plastic bucket, it will froth and neutralize very quiclky (seconds to a minute). Then fill the bucket with water, let the remaining limestone settle, and the clear water will now be charged with calcium nitrate ions and if the acid were fairly strong also with magnesium nitrate ions. Use the water."

Just came back here to read up & did a little experiment with about 3-4 Tbls. vinegar (5% acidity) & added about 2 Tbls. of pelletized lime. It foamed up all right LOL. I can't find any nitric acid around here. I remember someone asking if they can make their soil more acidic if they added vinegar. Is that true? What do you think of the vinegar/lime? Would this work well for plants in CHC? Thanks
Patty

Patty, send me a private message with your address, and I'll send you some Calcium Nitrate. - Millet