How can I remove sodium from my irrigation water?

Question

I'm a grower of bedding plants, perennials, shrubs, and trees. Recently I began to have some problems with quality. A water test revealed a high sodium content in my well water (230ppm). I need to reduce the sodium, and reverse osmosis is not feasible. The calcium level is low (2ppm) so I'm adding a flow-thru tank and adding calcite. Are there any oxcides that can remove the sodium from the water?

Answer 1

1.  230ppm Na+ does not sound unreasonably high...are you certain Na+ is the culprit?

2.  Why are you adding Ca++ to the water?

3.  No to oxides.

4.  Passing the water thru a cation exchange resin column (in the H+ cycle) will replace the Na+ with H+, but this wd be expensive in equipment, material and time (the column must be regenerated from time to time with acid to replace the Na+ on the column with H+).

5.  Ordinnary water softeners will not do the job...they are designed to replace 'hard' ions eg Ca++ with 'soft' ones eg Na+...just the opposite of what you want to do.  (But a water softener expert may be able to advise you re the resin column...if you think you can afford the system.)

Answer 2

Best and cheapest way is a water softener

Answer 3

Sodium is virtually impossible to precipitate out of water by chemical means. Adding calcite will play no role in reducing the Na level, but will increae the Ca++ level. Is this what you want to do?. Using an ion exchange bed, which will replace the Na+ ions with H+ ions, will result in the production of HCl in the water which will be more harmful to your plants than the sodium was. Reverse osmosis appears to be the only way, I'm afraid.