The correct pH for aquariums varies from fish to fish. But what is the right pH for bettas? And how can you change your pH if your level is off?
So, what pH do bettas like? Betta fish prefer a pH level between 6.5 and 7.5. Luckily, you can raise or lower your pH if it doesn’t naturally fall within this range.
Water chemistry can be tricky to understand, but pH is a good and easy place to start. We will discuss factors that influence pH, how to change your pH to better suit your betta, and possible impacts of pH changes.
Table of Contents
What should the pH Level Be in a Betta Fish Tank?
The pH level should be between 6.5 and 7.5 if possible. However, it is possible for bettas to live and thrive between 6.0 and 8.0. These ranges cover most, but not all, tap water.
If your water is either higher or lower than the maximum ranges, you will need to either change it or consider keeping a different species of fish.
Keep in mind that water straight from the tap will not show its true pH. To see what your pH actually is, you will need to test the water after leaving it out for 24 hours. As the water is pushed through the pipes, it tends to gain or lose certain gasses that impact the pH.
It takes about 24 hours for the gases to stabilize, and the pH can change more than a whole degree after the 24-hour period. Once you can test the true pH, you can make any necessary adjustments.
Buffering Capacity and pH
Betta fish prefer soft water, which often occurs at a lower pH. It is possible to have harder water at a lower pH, but this is rather rare. The reverse is also true; higher pH water is normally harder.
The “hardness” of water simply depends on the mineral content. Soft water has very low mineral content, while hard water has a high mineral content. The mineral content itself doesn’t necessarily impact the pH.
However, the buffering capacity of water, often measured by kH (carbonate hardness) has a significant impact your ability to change the pH. Hard water has a high buffering capacity while soft water has a low buffering capacity.
Buffering capacity is often seen as a good thing; unless you are trying to change the pH. Soft water can have the pH altered easily, while hard water is more difficult to change. When you change the pH of soft water, you should do so very slowly and carefully.
Soft water often changes more quickly and drastically than predicted, which can harm fish. On the other hand, hard water needs to be treated more aggressively to successfully change the pH.
Can Bettas live in high pH Water?
If you have water with a high pH, around or above 8.0, you may want to rethink bettas. Betta fish simply cannot live outside of their pH comfort range.
The same goes for water with a low pH. Keeping a betta in the wrong type of water, whether it’s the pH or the hardness that is wrong, will not end well. They are simply not able to adapt and will die prematurely.
What Causes High pH in Aquariums?
As previously mentioned, water with a high pH tends to be very hard. Certain dissolved minerals, which contribute to the hardness level, also raise the pH. The type and amount of minerals will vary depending on location, but most tap water is not overly hard.
High pH above 8.0 only happens in homes that get their water from wells. Well water tends to be very hard and unsuitable for bettas. You will either need to use another water source or choose a different fish. Domesticated bettas, aka betta splendens, aren’t the only ones out there, and some betta species even prefer rock hard water.
Certain decorations, primarily natural rocks, can also raise the pH. While they are beautiful decorations, and most are chemically inert, there will always be some that raise the pH, especially if you have soft water. If you are seeing drastically different pH’s between your tap and your tank, there is something in your tank that is causing them.
How to Naturally Lower the pH of an Aquarium
If you have water with a high pH and high buffering capacity, it can be difficult to lower, but not impossible. Natural methods normally take a bit longer than store bought methods, but they are more stable and have longer lasting effects.
Plant matter, CO2 injections, and vinegar are some of the more popular methods. As plant matter decays in aquariums, it releases tannins. Tannins can make the water appear darker, but it has beneficial antifungal and antibacterial properties, as well as the ability to lower the pH.
Aquarium driftwood, Indian almond leaves, peat moss, and certain seed pods are commonly used in aquariums. It is not recommended to gather these yourself, as you can’t be sure they weren’t treated with pesticides or insecticides. If either of those get into your aquarium, your fish will die.
Driftwood, particularly Malaysian and Mopani driftwood, is the most effective method. These types of driftwood are well known for the massive amounts of tannins they release.
Carbon dioxide injection is used in heavily planted tanks. It should not be used in tanks without plants, as you can suffocate your fish. When done properly, the pH will remain steady, but below the tap water pH. It also allows you to grow incredibly brilliantly colored plants that can’t survive on the normal amount of CO2 in aquariums.
Vinegar dosing, while more common in saltwater aquariums, can be used in freshwater tanks. Dosing just a little bit will lower the pH over the next few hours, and if monitored carefully, it can be a very successful and safe method.
What Causes Low pH in an Aquarium?
If you aren’t intentionally trying to lower the pH of your tank, some plants and decorations can have unintended consequences. All plants in planted tanks constantly shed decaying material. If left unattended, it will lower the pH.
Decorative driftwood, leaf litter, injected carbon dioxide, liquid carbon dioxide, and some fertilizers will also cause a low pH.
One of the most troubling causes of an abnormally low pH is Old Tank Syndrome. Symptoms of this syndrome include a rising hardness level and falling pH. Old tank syndrome is caused by a buildup of waste and increasing mineral content.
This happens over a period of several months and normally has to do with improperly cleaned substrate and filter material and topping off evaporated water more than changing it.
Weekly water changes, filter cleanings, and vacuuming the substrate eliminates the probability of this syndrome developing. It also helps to keep the pH more stable and closer to the tap, in case you have any decorations causing a change.
How to Naturally Raise the pH in an Aquarium
Naturally raising the pH of an aquarium isn’t difficult and is often quite fun. It involves adding a few more decorations.
Since lower pH water doesn’t have a high buffering capacity, you don’t need to add too much to make a difference. Seashells, coral, limestone, and other rocks are very effective at raising the pH. There are a lot of beautiful seashells that are suitable for aquariums, and most of them have smooth edges, which are perfect for betta fish!
If you don’t want anything visible in the tank, and you have a canister or hang on back filter, you can simply add the calcium source there.
How to Raise and Lower pH With Store-Bought Products
The good thing about store products that claim to lower or raise the pH is that they actually do. Just as claimed, they will indeed raise or lower the pH. With a catch.
These products do not always raise or lower the pH as much as they should, or they could make too much of a difference. Most do not have instructions based off of the preexisting pH and buffering capacity, so the change could be much larger or smaller than expected.
The change in pH also tends to only last a few hours before springing back. Large swings in pH can send fish into shock, which could result in death.
It is possible to effectively use these products to make lasting changes in pH. As long as you are aware of possible swings and monitor carefully, these products can be very successful. If you are measuring your water hardness, be aware that using them will show an increased hardness, but this increase won’t actually impact your betta.
In conclusion, betta fish prefer a pH between 6.5 and 7.5, though there is a wider habitable range. The pH of an aquarium can be altered, both higher and lower, in order to correct poor water parameters. Both natural methods and store-bought methods can both be effective, but natural ones tend to be more stable.
