How to raise pH in fish tank?

What is pH?

The concentration of dissolved hydrogen ions in the water base is represented by pH; the larger the concentration, the lower the pH value. The pH scale runs from 0 to 14, with less than 7 being acidic and more than 7 being alkaline.

Why is pH significant in a tank?

pH may not be important to us, but it is critical for fish in the water. Different fish are accustomed to different pH levels (or nearly the same scale), and a low pH level may be innocuous to one fish but burn the skin of another; a low pH level can be detrimental and stimulate the growth of harmful bacteria. That is not something we want to see thrive! Furthermore, fluctuations in the pH range can cause issues for fish, so checking the pH level in the water will help you establish if it is good for your fish and make required adjustments.

What is the ideal pH level for a tank?

Of course, depending on what pH level your fish is acceptable for, most fish require a pH range of 6.8-7.6. When it comes to fish tanks, the tank should be as close to their natural habitat as feasible.

What causes a tank’s pH to drop?

Soft tap water: If the calcium and magnesium level of your tap water is low, it is considered soft water. These minerals serve as acid neutralizers, causing pH levels to fall.

Inadequate maintenance: If the water is not changed on a regular basis, fish excrement and plant debris collect, raising nitrate levels, reducing pH, and encouraging algae to grow.

Tannins: The presence of ornamental driftwood might cause tannins to be released, resulting in a minor fall in pH levels. However, this is not a problem because a small bit of carbonated tap water usually balances it out.

Excess CO2 is caused by inadequate aeration. While CO2 is important to healthy plant growth in freshwater tanks, it can be damaging to delicate saltwater reef tanks by lowering pH levels, inhibiting coral growth, and encouraging the growth of dangerous bacteria. An airtight tank can also cause extra CO2 to accumulate in the water, lowering the pH.

How can you raise the pH of a fish tank?

Water changing. If the nitrates (described above) are causing the pH level in the water to drop, the simplest solution is to change the water; you can replace half of the water every other day to avoid severe pH fluctuations. You can change the water every other week once the pH has stabilised.

Adding baking soda.  Baking soda (NaHCO3) raises the pH of water. 1 teaspoon baking soda per 5 gallons (19 litres) of water is recommended. Remember that because there will be other decorations in the tank, the amount of water cannot surpass the tank’s maximum capacity. Gradually increase the doses and wait a day or two before adding more until you achieve the ideal pH level. It is critical to add baking soda every time you change the water in your tank to maintain the pH level. However, when altering the pH with any form of chemical, exercise caution.

Set up a filtration system. The pH of the water column can be lowered if CO2 accumulates in it via fish respiration. As a result, it is strongly advised that you use a filter in your tank to avoid this problem. The filters enhance gas exchange in the tank by improving water circulation and surface agitation. Due to insufficient aeration, unfiltered tanks frequently have low pH levels.

Change or boil the wood. Instead of actual wood, you can remedy the problem by adding resin decorations that look like wood. If you want to save the wood, soaking it in water or boiling it may help remove the tannins. Keep in mind that tannins are released by peat moss.


There are several methods for raising the pH levels in your tank, but it is always preferable to use natural and progressive approaches rather than relying on chemicals to obtain the ‘ideal’ pH. The methods described in this tutorial can assist in overcoming issues caused by low pH levels.

However, maintaining a consistent pH level is equally vital because changes in water chemistry can be lethal to some of the more fragile fish species.

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