Introduction
When caring for tropical amphibians like mossy frogs, dart frogs, or tree frogs, water quality isn’t just important — it’s life support. Many keepers use reverse osmosis (RO) water to remove chlorine, heavy metals, and impurities. But without remineralisation, RO water can do more harm than good.
This article explores how to properly use RO water in amphibian setups, why remineralising is essential, and how to avoid tragic, preventable losses.
What Is Reverse Osmosis (RO) Water?
Reverse osmosis is a filtration process that strips water of virtually all dissolved solids, including:
- Chlorine
- Fluoride
- Calcium
- Magnesium
- Iron
- Trace minerals
While this creates very pure water, it’s too pure for frogs. RO water lacks the essential ions and electrolytes that frogs (and live plants) rely on to regulate their internal chemistry.
Why Pure Water Can Be Dangerous for Frogs
RO water, when used alone, can lead to:
- Osmotic stress – cells swell or burst due to a lack of balancing minerals.
- Electrolyte imbalance – frogs cannot regulate hydration or nerve function properly.
- Shedding issues, neurological symptoms, or sudden death.
This isn’t rare. Many experienced keepers, even with the best intentions, have lost frogs by forgetting to remineralise RO water.
What Is Remineralisation?
Remineralisation means adding safe, amphibian-appropriate minerals back into RO water. It restores water hardness and essential trace elements.
Common products include:
- SaltyShrimp GH+ (for soft-water species)
- Seachem Replenish
- DIY mixes with calcium chloride, magnesium sulfate, and potassium
Always use a TDS meter (Total Dissolved Solids) to measure mineral levels. Most frogs do well in the 80–150 ppm range, but this varies by species.
How to Safely Prepare Water for Frogs
- Start with RO or distilled water.
- Add remineralising product, per the label or custom ratio.
- Check with a TDS meter — adjust if needed.
- Let water sit for 24 hours if using in misting or reservoirs (to reach equilibrium).
- Use consistently for misting, top-offs, and water bowls.
When to Use Tap Water
If your local tap water is low in chlorine and not too hard, you can:
- Dechlorinate it using a product like Seachem Prime or ReptiSafe.
- Mix it 50/50 with RO water to balance minerals naturally.
Still, for delicate species like Theloderma corticale, RO + remineralised water remains safest.
A Cautionary Tale
At Frogfather HQ, we lost one of our mossy frogs after forgetting to remineralise freshly filled RO water. It was a heartbreaking and entirely preventable mistake. This is why we now double-check every misting tank and reservoir. If this article helps even one frog keeper avoid that loss, it’s worth it.
Recommended Products
✅ TDS Meter – check your water’s mineral levels.
✅ GH+ Replenisher – restores calcium, magnesium, and trace elements.
✅ Safe Water Storage – store water in clean, labelled containers.
✅ Digital Thermo-Hygrometer – track changes if water chemistry causes stress.
