Most likely you have high Nitrates, which will lower your pH, or you just changed water, and used water that you don't usually use, or you added something that changed it.
It is important for a fish aquarium owner to purchase a ph probe for their tank. It helps measure the pH levels in the water. Certain types of fish will only survive in water with a certain pH level and one would need to know what their tank pH level is for their fish to survive.
check the pH balance for ammonia
When setting up an aquarium we must allways try and simulate the fish's natural environment as best as possible. If a fish is found in water with a PH range of 6.0 - 7.0 that will be the range we would try and keep with-in an aquarium. As for the question "Why should the pH for tropical fish be 7" that is a bit of a trick question as different tropical fish have different PH ranges. www.justaddwateraquariums.com.au
It differs from aquarium to aquarium but it is generally just about seven and can go to about eight. It should never be below seven because that is too acidic for fish. Different fish prefer different pH. Some fish will like it around seven, others around eight and some in the middle of the two.
The ideal pH level for maintaining a healthy aquarium water pH is typically between 6.5 and 7.5. This range is suitable for most freshwater fish and plants to thrive in a stable environment.
you can use pH up and pH down but it keeps going down and down if you pH is 8.0 its bad. if you have rocks in that are not chalking take a few out and try putting in bogwood it makes it go down to.
Api Wardly.
To neutralize acidic aquarium water and create a suitable environment for fish, you can add a pH buffer or use crushed coral or limestone as a substrate. Regular water testing and monitoring can help maintain a stable pH level for your fish.
A good buffer recipe for maintaining pH levels in an aquarium is a mixture of baking soda and water. This can help stabilize the pH levels and keep them within the ideal range for fish and other aquatic life.
Normal pH level is around 5.5-6.5,anything higher than 7 can b deadly to ur aquarium,fish stores usually sell a few different products to reduce or increase ur pH value such as PH MINUS.
The fish are drinking it. Get rid of the fish
To adjust the pH level of your aquarium water to make it more acidic, you can add substances like peat moss, driftwood, or commercial pH-lowering products. These can help lower the pH and create a more acidic environment for your fish. It's important to monitor the pH levels regularly to ensure they stay within the appropriate range for your aquarium inhabitants.