Your anthurium can handle anthurium tap water just fine in most cases. But it does better with filtered or rainwater over the long run. Tap water won't kill your plant right away. But the chemicals in it can build up in the soil and cause brown leaf tips after a few months of use.
I noticed this problem with my own anthuriums after about four months of straight tap water use. The tips of the leaves started turning brown and crispy, and I couldn't figure out why at first. My watering schedule was fine and the light was good. Once I switched to filtered water from a simple pitcher filter, the new leaves came in clean and green within three weeks. The brown tips on the old leaves didn't heal, but no new damage showed up after the switch.
The issue with tap water comes down to what's dissolved in it. Most city water contains chlorine and fluoride added during the treatment process. It also carries minerals like calcium and magnesium that vary by region. Over time these chemicals build up in your potting soil. The mineral buildup raises the soil pH above the 5.5-6.5 range that anthuriums prefer. You may even see a white crust forming on the soil surface or around the pot's drainage holes. That crust is mineral salt deposits from your tap water.
So what is the best water for anthuriums if tap water causes problems? Thompson and Morgan suggest rainwater, distilled water, or cooled boiled water as the top picks for your plants. Each of these options has far fewer dissolved minerals than what comes from your faucet. Filtered water from a standard pitcher works well too and costs less than buying distilled by the gallon.
Using rainwater for anthurium plants gives you the best results of all the options. Rain has a slightly acidic pH that matches what anthuriums prefer in the wild. It contains no chlorine, no fluoride, and very few minerals. I collect rainwater in a 5-gallon bucket on my porch and use it for all my tropical plants. One good rainstorm gives me enough water to last about two weeks for my small collection. If you have the space to collect it, your anthuriums will thank you with healthier leaves.
If tap water is your only option right now, you can still make it work for your anthurium. Fill a container with tap water and leave it open on the counter for 24 hours before using it on your plant. This lets the chlorine gas escape into the air on its own. It won't remove fluoride or heavy minerals, but it does cut out the harshest chemical. You can also flush the soil with extra water every month or two to wash out built-up salts. Just pour water through the pot until it runs clear from the bottom for about 30 seconds straight.
Your anthurium tap water choice comes down to what you can manage in your daily routine. The best water for anthuriums is rainwater or filtered, but treated tap water works fine as a backup plan. Don't stress over making it perfect every single time. Just avoid ice-cold water since it can shock the roots and slow growth down. Use room temperature water every time you water and your anthurium will stay healthy. It'll keep pushing out new leaves and blooms for you season after season.
Read the full article: Anthurium Plant Care and Growing Guide
