Can I use tap water for houseplants?

Yes, most UK houseplants are fine with tap water. However, some sensitive species — particularly calatheas, dracaenas, spider plants, and carnivorous plants — can be damaged by fluoride and chlorine in tap water. If you notice brown leaf tips on these plants, your tap water chemistry is likely the cause.

Does fluoride in tap water harm plants?

Yes, fluoride is the most damaging tap water chemical for sensitive houseplants. Even at the low levels found in UK water (0.1–1.0 ppm), fluoride accumulates in leaf tips and causes irreversible brown, crispy edges — especially on calatheas, dracaenas, spider plants, ti plants, and peace lilies. Areas with fluoridated water supplies (parts of the West Midlands, North East, and East of England) have higher levels.

Is hard water bad for houseplants?

Hard water (high in calcium and magnesium) is generally safe for most houseplants but can cause problems over time. It raises soil pH, which prevents acid-loving plants like azaleas, gardenias, and blueberries from absorbing iron. You may also see white mineral deposits on soil and pots. Orchids, ferns, and carnivorous plants prefer soft or distilled water.

How do I make tap water safe for sensitive plants?

The easiest methods are: (1) Leave water in an open container for 24 hours to let chlorine evaporate (this does NOT remove fluoride or chloramine). (2) Use a carbon filter jug — removes chlorine and some chloramine but not fluoride. (3) Collect rainwater — free and ideal for all plants. (4) Use distilled or reverse-osmosis water for the most sensitive species like calatheas and carnivorous plants.

Is Your Tap Water Safe For Houseplants? UK Guide

Can You Use Tap Water For Houseplants?

Most UK houseplants do perfectly well with ordinary tap water. But if you've ever noticed brown tips on your calathea, crispy edges on your spider plant, or a struggling dracaena, your tap water chemistry could be the culprit.

Three things in UK tap water can cause problems for sensitive plants: fluoride, chlorine/chloramine, and high mineral content (hard water). The levels vary enormously by region — what's fine in Glasgow might cause problems in Birmingham.

Fluoride: The Biggest Problem for Houseplants

Fluoride is the single most damaging tap water chemical for sensitive houseplants. Unlike chlorine, it doesn't evaporate when you leave water standing overnight. It accumulates in leaf tissue and causes irreversible brown, crispy leaf tips and margins.

Plants most sensitive to fluoride:

Calatheas (prayer plants) — extremely sensitive
Dracaenas (dragon trees, corn plants)
Spider plants (Chlorophytum)
Ti plants (Cordyline)
Peace lilies (Spathiphyllum)
Carnivorous plants (Venus flytraps, sundews)

UK fluoride levels range from near-zero to around 1.0 ppm. Some areas have naturally occurring fluoride, while others — parts of the West Midlands, North East England, and East of England — have fluoride added to the water supply. Learn more about fluoride in UK tap water.

Chlorine and Chloramine

All UK water companies add chlorine or chloramine to disinfect the water supply. At typical UK levels (0.2–0.5 ppm), chlorine is unlikely to cause visible damage to most houseplants. However, very sensitive species and seedlings may benefit from dechlorinated water.

Chlorine evaporates if you leave water in an open container for 24 hours. Chloramine (used by some water companies as a longer-lasting disinfectant) does not evaporate easily — you need a carbon filter or treatment drops to remove it. Check chlorine levels in your area.

Hard Water and Soil pH

Hard water is high in dissolved calcium and magnesium. Over time, watering with hard water raises your soil pH, making it more alkaline. This is fine for most houseplants, but can cause problems for acid-loving species:

Azaleas and gardenias — need acidic soil (pH 4.5–6.0)
Orchids — prefer soft water, hard water leaves mineral deposits on roots
Ferns — many species prefer slightly acidic conditions
Carnivorous plants — must have mineral-free water (rainwater or distilled only)
Blueberries — need very acidic soil, hard water gradually raises pH

You can spot hard water problems by white crusty deposits on the soil surface or pot rims. Check your water hardness.

Best Water for Different Plant Types

Most houseplants (pothos, monstera, philodendron, succulents, cacti): Tap water is fine. No treatment needed.

Sensitive tropicals (calatheas, marantas, stromanthe): Use filtered water, rainwater, or water left standing 24+ hours. If you're in a fluoridated area, use distilled or RO water.

Orchids: Prefer soft water. If your area has hard water (above 120 ppm), consider using filtered or rainwater.

Carnivorous plants: Rainwater or distilled water only. Tap water — even soft tap water — contains too many minerals and will kill them.

How to Make Tap Water Plant-Safe

Leave it to stand (24 hours) — lets chlorine gas off. Free and easy, but does NOT remove fluoride, chloramine, or minerals.
Carbon filter jug (e.g. Brita) — removes chlorine and improves taste. Does not fully remove fluoride or reduce hardness.
Collect rainwater — naturally soft, fluoride-free, and free. The gold standard for sensitive plants. Use a water butt or even leave a bucket outside.
Reverse osmosis (RO) water — removes virtually everything. Best for carnivorous plants and very sensitive species. Available from aquarium shops or home RO units.
Distilled water — mineral-free, available from supermarkets and chemists. Good but more expensive than rainwater.

Check Your Tap Water for Plants

Enter your postcode on WaterGrade to see your local fluoride, chlorine, hardness, and pH levels — and find out if your tap water is suitable for your houseplants.