Is tap water safe for aquarium fish?
Written by
John Williams
Reviewed by
Prof. Henry Webster, Ph.D.Many newbies wonder whether the tap water in their home aquarium is safe for their fish. The answer requires some detailed discussion. I learned this at a great cost to my fish when I first started the business and put untreated water in the aquarium. Proper treatment transformed the character of the tap water, making it suitable for aquatic life to thrive.
Chlorine Neutralization
- Use liquid dechlorinator following bottle instructions precisely
- Treat all tap water before adding to aquarium
- Chlorine kills beneficial bacteria in minutes
Heavy Metal Removal
- Test for copper and zinc using aquarium test kits
- Choose conditioners that detoxify heavy metals
- Copper levels above 0.03 ppm harm invertebrates
Temperature Matching
- Measure tank water temperature accurately
- Adjust new water within ±2°F (1°C)
- Sudden temperature changes cause fish stress
Always allow conditioned water to settle for an hour before introducing it into your aquarium. This permits complete chemical neutralization. I always keep some water prepared in clean buckets near my aquarium. Matching the temperature of the water avoids thermal shock, which otherwise results in stress on the fish. Following these few steps is essential for creating a safe habitat.
Select conditioners that effectively neutralize both chlorine and chloramines. Increasingly, municipalities are treating their water supply with chloramines. Most dechlorinators will not completely neutralize chloramines. Always read the label. Higher quality conditioners will cost a bit more money, but will effectively protect sensitive species better.
Assess your tap water source for quality on a seasonal basis. The quality of your water changes from one season to another. Heavy rains build up the mineral content. Pipe maintenance can create temporary issues with water quality. Have your kits handy for emergency changes if necessary. It is better to be safe than sorry when unexpected things happen.
Well water also needs special care. It can often have high priorities for minerals. Test for the calcium and magnesium content, which relate to water hardness. Some fish may need specific mineral thresholds. Be aware of the characteristics of your source water.
Read the full article: Essential Fish Tank Maintenance Guide for Beginners
