Is Calcinit Ag Grade by Yara http://www.yara.us/en/products/product_range/nitrogen_fertilizers/ca_ag_grade.html a suitable form of calcium nitrate for use in cation exchange when preparing CHC's? This is the water soluble form. Will the ammonium nitrate be a problem for this purpose, assuming of course I am not potting up seedlings? My high school level of chemistry proficiency has faded into the distant past; however, I hope I got it right.

Kent

Calcinit Ag Grade, will work just fine. If you purchased your CHC from The Crystal Co. they have already rinsed and squeezed the chips three times. For citrus all you will need to do, is the Cation exchange, with the Calcinit and Epsom Salts. Lastly, I never rinse the CHC again after the Cation exchange with the Epsom salts & Calcium nitrate, but just go ahead and make my medium blend and transplant the tree. - Millet (1,376-)

Millet,

What concentration do you use, like how many ppm MgSO4 and CalciNit? I don't plan to rinse the chips either if I can get away with it by using a more diluted solution. Usually, for CEx, stronger solution is prepared, that is why the need to rinse afterwards.

Thanks,

Joe

Joe, I do the chips in a 55-gallon drum, I add 3 ounces of both MgSO4, and Ca(NO3)2. - Millet (1,376-)

Thanks! Thats about 408.5 ppm of MgSO4 hydrated salt and 408.5 ppm of Calcium Nitrate crystals.

The real ppm without the hydrated crystals could be lower.

I have read somewhere, (don't recall where) that a slightly higher ppm nutrient rate needs be used when a new CHC medium is first being used. Wish I could find the article where I read it. Therefore, I apply nutrients at 300 ppm N on a new CHC medium. - Millet (1,376-)

Millet, do you ever replenish the calcium component in your CHC plantings through the use of lime, gypsum or occasional calcium nitrate treatments in between repottings? If so, which is the best approach for city water and for well water sources? Barbara

Why do you have to soak the CHC with Mg and Calcium? Does this practice set the medium to a nutural PH or something?

Babara, no I do not add any extra calcium. My well water contains plenty of calcium, to take care of the trees needs. I do not know about water supplies in Eastern United States, but most all water in the west contains dissolved calcium. - Millet (1,057-)

Thank you, Millet. We sit on a fair amount of limestone (limestone quarries within a few miles of our town), so I know that we should have a good amount in our groundwater, too. Our borough water is supplied by a combination of well and spring water, so I guess I should be okay. The last analysis supplied did not indicate actual numbers, just that it was within drinking water standards.

I wonder if it would hurt to give them an occasional dose of Ca(NO3)2, since I have it. Maybe in combination with epsom salt, dissolving both in water when I give them epsom salt. Any thoughts on that? Barbara

If you grow tomatoes, tomato plants love Calcium Nitrate. Fertilizing tomatoes with Calcium Nitrate, eliminates blossom end rot. Applying a little Calcium Nitrate would be fine for your trees. - Millet (1,055-)

Thank you, Millet. I love tomatoes, and plant many every year. I did not know they responded so well to Calcium Nitrate. We had a lot of blossom end rot this year in our area, it was quite frustrating. I look forward to giving that a try this summer. Barbara

Yes. His answer was in response to this:

Quote:

I wonder if it would hurt to give them an occasional dose of Ca(NO3)2, since I have it. Maybe in combination with epsom salt, dissolving both in water when I give them epsom salt. Any thoughts on that?

Barbara