in the US reverse osmosis filters are available that are very inexpensive. For a small orchid collection you can use a unit that attaches to your kitchen faucet. Orchids thrive with R/O water, and you will find that their health and vigor is easily worth the cost for the R/O unit.
Keep in mind you need to use a complete fertilizer that includes minerals/micronutrients to replace the minerals R/O removes.
Keep in mind you need to use a complete fertilizer that includes minerals/micronutrients to replace the minerals R/O removes.