Water Parameter Reference
Look up safe ranges and test methods for pH, ammonia, nitrite, nitrate and more.
| Parameter | Safe range | Danger threshold | Test method | Test frequency |
|---|---|---|---|---|
| pHNeutral to slightly acidic or alkaline is fine; avoid sharp swings. | 6.5-8 ppm | below 6.0 or above 8.5 | pH strips / electronic pH meter | Once a week |
| Ammonia (NH₃)Must read 0; any reading is dangerous. | 0 ppm | over 0 ppm | Ammonia test kit | Daily in a new tank, then weekly once stable |
| Nitrite (NO₂⁻)Must read 0; it is highly toxic. | 0 ppm | over 0 ppm | Nitrite test kit | Daily in a new tank, then weekly once stable |
| Nitrate (NO₃⁻)Keep it under 40, ideally under 20; if higher, change water. | 0-40 ppm | over 40 ppm | Nitrate test kit | Once a week |
| Water temperatureSuitable range for warm-water turtles such as red-eared sliders. | 24-28 ppm | below 20°C or above 32°C | Thermometer / heater display | Check daily |
| Dissolved oxygenNitrifying bacteria need oxygen, and so does the turtle's breathing. | 5-99 ppm | under 5 ppm | Dissolved oxygen test kit / watch the turtle's breathing | Test when something looks off |
Testing advice
While a new tank cycles: Test ammonia and nitrite daily; only call it stable once both read 0 for 7 days straight
Routine upkeep: Test nitrate and pH weekly, and change water as soon as anything looks off
If something is wrong: If ammonia or nitrite is over the line, change 50% at once; if nitrate is high, change 1/3