| Water, Hard | Comments |
|---|---|
| WATER, HARD: Causes Calcium Deposits on Cattleya Leaves The acidification of water from the hose gradually dissolves the deposits; see method described, A69-126; A71-609 | 0 |
| WATER, HARD: Characteristics The critical factor is the soluble salt content; over 150 ppm. of calcium carbonate (CaCo/3) is hard, soap does not produce good lather; waters with less than 125 ppm. are excellent; up to 500 ppm. are all right; 500 to 800 are usable with caution. F80-8 | 0 |
| WATER, HARD: De-ionized Water for Plants For a few small plants one can buy the kind of water sold for steam irons in areas where the local water has a high sodium content. OD79-53 | 0 |
| WATER, HARD: Deposits on Tree-fern Rafts To dissolve these use a little nitric acid at pH of 4.0 to 4.5; add a few drops of dilute nitric acid to a plastic bucket of water and soak the rafts for 1/2 hour. A75-680 | 0 |
| WATER, HARD: Devices Available for Removing the Cause There is no simple device for removing calcium and magnesium from tap water; water-softeners create water unsuitable for orchids; demineralization units are expensive; paphiopedilums grow in limestone soils and are not harmed by "hard" water; possible to acidify hard water with citric or nitric acids. A72-204 | 0 |
| WATER, HARD: High in Calcium and Magnesium Salts Its nature and characteristics and suitability for growing; has high electrical conductance; comments on water-softeners; refer to A67-466+; AH39 | 0 |
| WATER, HARD: Near Maximum "hardness Index" If the water coats pots and plants with lime residue, perhaps rain water should be collected for periodical use; demineralizer units are expensive but laboratory models are more moderate; address given. A73-709 | 0 |
| WATER, HARD: Softened with Soda Ash Do not use this on plants. A67-466; A78-812 | 0 |
| WATER, HARD: With Activated Charcoal to Remove Calcium It will not work; only certain types of organic compounds are filtered out; units for doing the job properly are not cheap; best bet is to catch rainwater. A74-433 | 0 |