Fanciers of Cryptocoryne have a firsthand experience in challenges of keeping these plants from Malay Archipelago. Most part of Cryptocoryne from this region lives in Sumatra and Kalimantan, as well as small adjoining islands. The variety of species is huge. Today science knows more than five dozen species and subspecies of Cryptocoryne that have found their home on these islands. Almost all of them, with rare exceptions (Cryptocoryne ciliata, C. pontederiifolia, C. wongsoi and some others), live in small forest streams and rivers with very soft and acidic water (pH = 4-6; TDS = 5-40 ppm). At the same time, the water in the Moscow water supply system is close to neutral and contains by an order more hardness salts (pH = 7-7.5; TDS = 120-200 ppm). Given the sensitivity of Cryptocoryne to fluctuations in water parameters, considerable challenges come up in their maintenance. Some plants “melt down” within a few days after planting, while others stop growing and decay for a long time until they disappear completely.
Figure 1. A small creek with Cryptocoryne scurrilis on an hevea plantation in Sumatra (Riau Province). рН = 4.0, TDS = 25 ppm.
Today I will share my experience on how to keep soft-water Cryptocoryne species in your collection and enjoy watching these interesting plants every day.