Discus Aquarium Water Parameters - pH

 pH – the measure of whether water is acidic (pH 1 to 7.0) or basic (pH 7.1 to 14). 7.0 is considered neutral. Tap water pH can vary depending on local conditions.  Most freshwater aquarium fish are happy at a pH of 6.8 to 7.6.  Its important to know what your pH is but it only ever becomes important if you start to keep specialist fish or you want to breed fish. 

For example, I can keep Rams, but they dont thrive and they dont seem to last very long.  I believe this is because my tap pH is above 8 and the water is very hard.  For Rams to thrive you need a lower pH and soft water.

You can keep tank bred Discus in tap water, but depending on your tap water I dont believe they are as happy as they can be.  I have tried to adjust the water to more suitable conditions for them using RO water and have seen them improve both in colour and behaviour.

Discus can survive in tap, but they thrive in RO!

TOP TIP -  pH changes are not good for any fish, so a stable reading is better than a reading that fluctuates around a perfect value.

You can control your pH with buffers.  I havent tried this but I imagine if you miss or the amount changes your pH can move around.

You can use RO water to lower a high pH, but RO water will be pH 7.

TOP TIP - Aeration is a good thing, it helps filters and keeps good levels of oxygen in the water.  But it will force carbon dioxide out of the water.  Dissolved carbon dioxide makes the water slightly acidic and can lower your pH.  Heavy aeration therefore can increase your pH.

When CO2 gas dissolves in water it creates carbonic acid. This will acidify the water and pH will decrease. 

So to lower pH you could

• Use a buffering solutions
• Inject Carbon Dioxide
• If your pH is above 7, RO water will bring down towards 7.