How to Adjust the pH in Your Aquarium

pH stands for “potential of hydrogen,” and it refers to the amount of hydrogen found in a substance. pH is measured on a scale that runs from zero to fourteen. Seven is neutral, meaning there is a balance between acid and alkalinity. The pH level of your drinking water tells us how acidic the water is.

Basically, the pH value is a good indicator of whether water is “hard” or “soft”. In general, a pH lower than seven means the water is acidic. And a pH between seven and fourteen means the water is alkaline or “basic”. The pH of pure water is always seven.

You may love to read how to clean aquarium gravel.

pH in an aquarium

If you are a fish keeper, or planning to be one soon, then you have to make some preparations, no doubt. And that does not mean to throw your fishes in a bowl full of tap water and call it a day. Among everything you need to set up, you also need to check the pH level in your aquarium and adjust if needed.

The pH level in your aquarium appropriately refers to the measure of hydrogen ion activity in the water.

Why is it important?

Learning about it and adjusting the pH level for your fishes is one of the basic important things a fish keeper has to do. This is because fishes naturally have their own preference to the pH level, as their survival depends on it. Each type of fish will have to live in an aquarium with the pH level set to their preference. Therefore, “balancing the pH level of an aquarium” means to adjust it, and making sure the aquarium water is neither too acidic, nor too alkaline for your fish. If not, serious problems will arise.

Your untreated tap water probably might be acidic to begin with. This means that the water you are about to use for your fish’s home, has high acid levels. The water can then become even more acidic, because of the activities of your fishes. Fish waste is mildly acidic. And when that slowly starts to build up over time, it will cause the pH to become more acidic.  

Aquarium water can easily become alkaline as well, if not already with the presence of calcium and magnesium within the tank. This also depends on matters like the corals, shells, gravel, etc in the tank that releases calcium and magnesium.

A problem with your filter, overfeeding, too many fish in the tank or improper aquarium maintenance can cause your water to become too acidic for the fish to survive in long term.

Like the examples above, factors like overfeeding your fish, too many fish in an aquarium that is too small, a problem with the tank filter, or very poor aquarium maintenance will cause your water to be far too acidic for your fish to live in in the long run. This will cause health problems for your fish if not properly adjusted to the needs of the type of fish you have. Observable symptoms include fish gasping, hyperplasia (thickening of skin and gills), and eye damage.

And on the other hand, tank water that is not acidic enough can cause some type of fish to be under a great deal of stress, and have health problems. For example, it can affect your fishes’ gills. If your fish is darting back and forth, check your pH, as this is a common symptom of high alkaline and may result in fish death as well. 

Placing a fish in a tank that has a drastically different pH than what the species is used, to can cause serious health problems for the fish.

One very important thing to know about the pH scale is that it is logarithmic. For example, a pH level of 5 is 10 times more acidic than a pH level of 6. And a pH of 4 is 100 times more acidic than a pH of 6.

So if your fish thrives in a pH of 7, but the water in your aquarium measures 8, your water is 10 times more alkaline than what it should be. If the pH is 9, then your fish are living in water 100 times more alkaline than recommended for the optimal health. So it is easy to see why even a small change in the required pH value can be stressful, and potentially fatal to your fish.

Keeping a fish that requires a pH of 8 to share the same tank water with a fish that requires a pH of 6 is very threatening to the lives of one or both of them. Therefore it is very important to match your type of fish to the appropriate pH level of water required as closely as possible. Afterwards it is important to keep it constant and always closely monitoring the pH to avoid any future problems and to catch on any problems that may arise in the future.

To change or not to change

There are chemicals that are suspended or dissolved in the water of the tank. These chemicals fall into three main categories: acids, bases, and buffers. Acids are chemicals that lower the pH level, making the water more acidic. Bases are chemicals that raise the pH of the water, making it more basic, or alkaline. Lastly, buffers are chemicals that can 'tie up' acids or bases and keep the water at a specific pH. Different buffers will keep the pH level at different values.

If you make the decision to change with the pH in your aquarium, this will be very easy to do if the water does not contain any buffers.

If you are lowering your pH, you will have to add an acid to the water. And as this acid neutralizes all the bases in the water, the water becomes neutral. As you add more acid to the water, the pH continues to drop and the water begins becoming acidic. You can continue this until the pH is where you want it.

However, if the water in your tank does contain buffers, then this process will be a bit more difficult. Like the process mentioned above, you need to add an acid to the tank water which will neutralize the bases. But in this case, the buffers in the water will cause the pH to remain high. Because of this, you need to add a higher amount of acid to neutralize the buffer. However, by the time enough acid is added to the water to overcome the buffer, the water will have enough acid to cause a sharp drop in pH.   

Changing the pH once means changing it every time you do a water change. Not only do you have to repeat the entire process with precise measure every time, you also have to make sure to not make any slight differences in the process of treating the water, because it can make dramatic changes in how the buffers behave.

Basically, fish keepers, especially first timers, usually make the common mistake of messing with the pH level out of worry for the fish. So, important as it is to keep the correct level of pH that suits well with your fish, how important is it to try and change it, and then constantly keeping that way, for better results? The answer mainly relies on the species.

Almost all fish are very tolerant of a wide range of pH in the water they live and thrive in. Unless you own or are planning to keep fishes with a very specific pH requirement, this should not really be a problem. Maintaining the current pH value can be done with simple measures, like cleaning the tank very regularly.

Drastic pH changes due to new materials or other factors such as overcoming a buffer in the water is certainly very risky. It will cause harm to not only your fish, but to your plants, and even to your biological filter. In most cases, buffers in the water are good for your tank. If the pH is buffered to a specific value, then things that are added to the tank will not change the pH level very easily, and this makes your water remain healthier and more stable.

Nevertheless, keeping the proper pH in check is no wonder a must for the well-being of your fish. If you are still too concerned with this, the best way to see if you should do something about the pH in the water tank is to test it.

There are many pH level testing kits available in pet stores, and online. Make sure to not make the mistake of buying a faulty one and getting inaccurate results. Research to find the best type of kit that gives you precise and correct results, and make decisions based on it afterwards. Test the tank water once a month.

How to adjust it

If you are sure that it is absolutely necessary to change the pH value of the tank water either by lowering or rising it, then there are several ways to do it. Here are the methods below to choose from:

1. Add natural driftwood

Driftwood will soften the water and help to gently lower the pH level. Add 1 or 2 pieces of natural driftwood that are small enough to fit in your tank. Driftwood acts as a natural filter to the tank water. It helps by removing contaminants that raise the pH value. One thing to note, though, is that driftwood is a great way to not only lower the pH, but to also color the tank water. If you are not into the whole yellow tank water vibe, then you can boil or soak the pieces before adding them to the tank community.

Soak the driftwood in a separate container, making sure it is completely submerged, and not floating. Leave it for one to two weeks prior to using it.

Or, boil the driftwood in water for about five to ten minutes to sterilize it. Either of these two procedures will avoid coloring the aquarium water. It is fine to leave the driftwood in the tank for several years on to lower the pH level.

But take caution. Buy and use the correct type of driftwood by making sure the one you are using are made for fish tanks. Always avoid the ones sold for reptiles as they contain dye, chemicals, preservatives that are harmful to your fish.

2. Add baking soda

This is a common method for raising the pH. First, remove the fish from the tank beforehand. The amount that is generally considered safe is one tea spoon of baking soda per five gallons of water. Next, dissolve the amount of baking soda in treated water and add it to the aquarium to slowly change the pH. After the pH is at the desired value, re-introduce the fish to the tank.

You should never make drastic pH changes, as this will have a severe harmful effect on your fish. Remember to start with one tea spoon per five gallons of water, and then slowly raise the pH incrementally. This will allow your fish to acclimate to the new tank conditions.

3. Add crushed coral

Rinse the crushed coral beforehand, and add small amounts of it in the filter. You can also use the crushed coral as the substrate of the tank, or you mix it in with a sand substrate, if it is suitable for your fish.

4. Add peat moss

Using peat moss is another very common and effective way to gradually lower the aquarium’s pH. You can buy it in pet stores, aquarium stores, or gardening stores. Make sure the peat moss you are planning to use is designed for use in fish tanks, as this will ensure it does not contain any chemicals or dyes.

Peat moss can be added to the filter in pellets, or in chunks. It also acts in a way similar to driftwood, by acting as a second filter. And just like driftwood, having untreated peat moss in the water of your tank will lead to discoloration. So before you add it to the tank, you need to prepare it so as to avoid discoloring the water.

Aquarists generally recommend treating the peat moss beforehand by soaking it in a different container of water for around three to four days.

The right amount of peat moss to use depends on the hardness of the water, so you will have to experiment to conclude the approximate amount, based on the size of the tank in order to reach the pH level required. 

Place the now treated peat moss in the aquarium by putting it in a filter bag, or a clean panty hose, or the filter of the tank itself. Do not add the peat moss straight into the water, because it will float and will not be effective.

Always start with small amounts, so as to not make any sudden drastic changes, and to bring down the pH level gradually with you monitoring it. Too much peat moss may cause the pH to drop below four, which is very low for most types of fish. Afterwards, you can judge based on the pH level in the tank to see if you need to add less or more peat moss over time.

You can keep the peat moss for as long as six months to a year, or once it starts to look old, damaged and needed to be replaced.

5. Add almond leaves

Almond leaves are very beneficial to fish and their habitat. Almond leaves have anti inflammatory properties, and they help to prevent diseases and other issues with fish. They add to the natural wild fish habitat look in an aquarium and provide natural and comfortable hiding spots for your fish as well.

Fish love the natural hiding spot and the ecological impact that leaves and other natural clutter can have on their environment. Last but not least, almond leaves naturally softens water, filters out contaminants, and therefore lowering the pH value.

You can find and purchase these dry and packaged leaves in both pet stores and online. Use two to three leaves for your tank. Almond leaves also release an amount of tannins in water, which can also slightly discolor the tank water. So, remember to soak the leaves for twenty four hours, to get the color leakage out prior to adding them into the tank.

Now, add the leaves to the tank by spreading them on the bottom and monitor. These leaves will need replacing after six months to a year, or when they start to look damaged and tattered.

6. Add plants

One last way of using nature’s handy equipment to change the pH value of your aquarium is to add plants to it. A planted tank will help, even though the effect of it is small. The carbon dioxide will lower the pH of aquarium water, making it more acidic. Oxygen has no effect on water pH. Therefore, when plants absorb carbon dioxide, thus removing it from the water, the pH value will rise. Look for plants that are suitable for your fish and for your tank in pet shops.

7. RO water

RO water refers to Reverse Osmosis. This indicates the natural de ionizing process of water purification that involves the use of semipermeable membrane that eliminates several types of molecules and ions. It does this by allowing water and smaller ions to go through, while keeping the heavier and the larger ions, like lead, chlorine, and other water pollutants. The result is fresher and softer water.

An RO unit will provide you with great help by keeping a constant and stable pH level, exactly what you need for your fish. It can filter up to ninety nine percent of water contaminants. An RO system will need occasional filter replacements, but is nevertheless a great long-term solution.

To use a RO filter, first select and purchase one keeping in mind the size of the aquarium you have, and your budget. RO filters come in two to four filtration stages. These stages go up both in price and in size.

2-stage RO units is the ideal choice if you have a smaller tank and limited space around your tank. They also come in good value for the price.

3-stage RO units are bigger and are much more suitable for larger tanks. Note that these are more expensive. They tend to last longer than 2-stage RO units.

4-stage RO units are the highest level of filtration you can buy for your tank. These are the largest model. They are usually the most expensive option out of them all.

If you are confused when selecting the right one for your aquarium, ask a salesperson, at the pet store for advice. You can also always take an aquarist’s advice.

When setting it up in your tank, first, run the water through the RO filter. Most RO filters will come with three tubes. One tube connects to your water supply. Another tube will run the water through the RO filter and then into a water collector, such as a bucket. The third tube will remove the wastewater that collects in the filter system. You can either throw the waste water that comes out of the unit away, or use it in your garden or yard.

The procedure of setting it up in your tank properly will turn easier when you carefully follow the instructions that come with the RO filter. You can also ask help from an aquarist, or from anyone at an aquarium store.

8. Chemicals

There are now many commercial products available on the market to choose from. These products are chemicals that changes the pH, either by lowering it or raising it. However, these are not generally recommended as the chemical compounds that either raise or lower the pH, do not maintain a stable value. This is only a temporary fix. The usage of these chemicals also have the potential to lead to large spikes or sharp drops of the pH value, harming your fish. The chemicals can also harm or cause dangerous side effects to your fish.

Paula Anderson

Click Here to Leave a Comment Below 0 comments

Leave a Reply: