That chalky white layer in your flowerpot, popularly called lime or mineral deposits, is made up of the exact materials that obstruct pipes, clouds shower doors and clog filters. Lime results in using tap water to irrigate houseplants, but it could also show up in the garden as the result of overwatering or over-fertilization. The lime deposit’s persistence results in its composition — and elimination depends on a little bit of family chemistry.
Real Lime
Lime deposits contain antioxidants gathered as water percolates through the aquifer — the layer of the ground that filters surface waters as they sink to the water table. Wells tap water trapped in stone — a sedimentary, or soft, rock composed of historical shells, corals and bones. Rich in calcium and magnesium, limestone leads other minerals to water, depending on the bedrock’s location. The calcium D from the mineral stew binds water and mud to mortar and silica and sodium carbonate in glass. Add water to calcium oxide and it forms calcium hydroxide, a compound that dries harder and faster, therefore plain water won’t dissolve the film it leaves.
Compounding the Problem
When high levels of calcium and magnesium collect in water over 60 parts per million, also called 1 grain — they mix with the hydroxides in soap to form the “soap scum” that anchors the lime deposits on the tub. Fertilizers contain potassium and potassium — and calcium — in chemicals that recombine in solution. To complicate things, water softeners use the ionization procedure to replace calcium with sodium in water, replacing minerals with sodium salt, therefore softened water isn’t a wise substitute for mineral-laden hard water.
More Is Not Better
Plants, like people, need a collection of minerals for development, but they require those vitamins in a digestible form. If they’re fed excessive or insoluble minerals in hard water or through over-fertilization, the excess will leech down through the ground. If lime collects on soil, cut back on water and fertilizer infrequently but deeply to induce excess minerals to leech through the ground. Containers for garden or houseplants collect large particles as sediment in a crust, some of it tough enough to withstand scrubbing. Watering thoroughly may wash fertilizer-borne mineral salts through pots, but tough water can merely replace fertilizer salts with more calcium chemicals.
Household Remedies
Two family chemicals used in food create safe, effective lime deposit cleaners. Utilize a solution with water, of either white vinegar, a acetic acid, or lemon juice, a citric acid, to dissolve lime. Start with just a 25 percent — up to a 50 percent option for thick layers — and wash tough container surfaces like plastic or enamel with a dish brush, and rinse well to remove deposits. Scrub clay pots immediately, scrub, and then soak in plain water immediately to remove any remaining acid. Scrub stubborn spots with full-strength vinegar plus a hard bristle brush, and rub or rinse with plain water to complete.