pH Lower

  • pH adjuster for fresh and saltwater
  • Increases acidity
  • Reduces alkalinity
  • Correct pH improves biological filter efficiency

About pH Lower

The pH of an aquarium is a very important, yet commonly overlooked aquarium water parameter. A correct, stable pH will help ensure a healthy aquarium environment. The pH of an aquarium can fluctuate due to biological or chemical activity within the aquarium. With pH Decreaser, the pH may be decreased to a desired level for aquarium inhabitants. Adjusting the pH to the proper level has an important influence on fish health and disease resistance.

Directions & Dosage

To decrease pH, add 5 ml (1 cap/1 tsp) per 20 gallons of water.
Check the pH of your aquarium water prior to dosing.
Depending on the initial acidity of your water, several doses may be required to reach the target pH. Wait approximately 10 minutes, re-check the pH level before adding more Fritz pH Lower.
If fish are present, limit pH change to 0.2 per day.


Size Treats Item Number
4 oz. N/A 80355
16 oz. N/A 81103



See below for frequently asked questions regarding pH Lower.

  • My pH seems to bounce back to a higher pH after a day or two. Why is that?

    In some areas of the country, the water is very alkaline. That means it contains many minerals which tend to raise the pH. Also, some aquarium decorations (limestone, seashells, crushed coral) add minerals which increase pH. If you are seeing this happen, please consult with a local fish store familiar with your local water supply for further guidance.

  • I’ve been warned about a sudden pH drop by my fish store. How do I avoid that?

    pH Lower contains a very mild acid. Acids work by removing the minerals that buffer the pH in the aquarium. It is possible to remove enough of the compounds that buffer the water (carbonates and bicarbonates primarily although other minerals play an important role) that the pH drops suddenly. Our directions are designed to prevent this from happening. However, if it does happen, you can add Fritz pH Neutralizer to restore some of the minerals that buffer the pH.

  • I’m not seeing any pH change on my test kit. What is happening?

    How soon after dosing are you testing the water? Give the product time to mix in the aquarium and change the water chemistry. We recommend testing several hours after dosing.

  • My pH is taking forever to change. Can I add more than the recommended dosage at a time?

    No. The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next higher value. For example, pH 6 is ten times more acidic than pH 7 and 100 times (10 times 10) more acidic than pH 8. So what appear to be small changes on a pH test kit or meter are actually pretty big changes. pH stability is more important to fish than a perfect pH. So if you are changing the pH, it is much better to do so gradually, over time and in small steps. Our directions allow for that gradual change in pH to avoid stressing livestock.

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