Q&A for How to Test pH in a Fish Tank

When the pH bottoms out on a repetitive basis, it creates stress on your fish. That may not manifest in immediate death, but you may lose your fish over time. Consider setting a CO2 injection up on a CO2 monitor, which would prevent the pH from fluctuating to levels that are too low.

Catfish thrive in a pH range of 5-7, while tilapia prefer a pH of 7-10, although you probably want to keep it closer to the 7 side of things. While some folks will claim otherwise, a lot of people have trouble housing catfish and tilapia together, so you may want separate environments here.

One teaspoon of baking soda per five gallons is generally a safe amount for small, incremental increases. It's best to remove the fish from the tank prior to raising the pH. Then simply dissolve the required amount of baking soda in some conditioned water and add it to the aquarium.

As the fish defecate and urinate, they produce ammonia, which then increases the pH of water. To correct it, the tank needs to be cleaned. For a temporary fix, you can remove some of the water and replace with fresh water. Just make sure the new water has been de-chlorinated.

The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution, and as such, is a measure of the acidity or basicity of the solution.

Generally aquarium pH kits read: 0-6 = low pH = acidic = Yellow - correct by adding a base (like calcium carbonate) = pH up 7 = neutral = Green 8-14 high pH = base/basic = Blue - correct by adding an acid = pH down

You have not cleaned out the tank recently. You need to do a 75% water change IMMEDIATELY if you want your fish to live. Repeat daily until the ammonia level is at 0.

If you have a pH of 1, then it wouldn't be possible for anything to live in the water since it would be essentially like stomach acid.

It's my understanding that chemical pH indicators are usually a weak acid. The drops are going to be a minuscule amount, so my guess is your fish will be fine.

7.0

You're not testing the soil, you're testing the water pH because the fish require particular levels of pH to live in.

A pH of 7.0 is the optimal level for crawfish. This is basically neutral, in that the water isn't acidic or basic.

No, vinegar is not a safe acid to use in the tank.

Research the types of fish you have and see what pH levels they need. Then get pH test strips, or an electronic tester to find your pH.

Between 6.8 and 7.6.

It's not very accurate. Buy API's test kit add 3 drops and wait five minutes. You will get clear results.

The best pH for goldfish is between 7.2 and 7.6.

Strip tests are not accurate, so if you're able to, consider buying a liquid test kit, such as the API freshwater master kit.

Almost all liquid aquarium solutions have instructions with specific measurements on the bottle. The majority of the time, the measurements are in gallons, so it is also important to know the size of your tank.