How to Raise pH in Your Fish Tank with Baking Soda

By Eddie Waithaka @aquariawise

How to Raise pH in Your Fish Tank with Baking Soda

Keeping fish in a home aquarium is a rewarding hobby, but there is a lot you need to know (and keep in check) to ensure your livestock remains safe and healthy.

Temperature and ph are at the very top, together with water quality.

However, different fish species have varying needs in terms of alkalinity, meaning you may need to buffer your water ph, depending on the fish you have.

One of the easiest ways to do this is using baking soda. Adding a teaspoon for every 5 gallons of water will gradually increase your water alkalinity by a few percentage points without causing your fish too much stress.

I like to dissolve the baking soda in a container with some of my aquarium water first before adding it to my main aquarium instead of just tossing the base in the tank.

How Does Baking Soda Do to Your Aquarium Water

A ph level indicates the alkalinity or acidity of any solution on a scale of 0 to 14.

The ph of the water you use in your fish tank will fall somewhere between this range, mostly between 6 and 7, which is ideal for some tropical fish though not all.

And since baking soda is a base that counters (neutralizes) acids, adding it to your aquarium will reduce your water acidity, making it more alkaline for fish that prefer hard, alkaline water (such as Malawi cichlids).

The best part is that baking soda is readily available, cheap, and easy to use, but you need to make sure you raise your water ph gradually to avoid shocking your finnies.

Perhaps, a good place to start is to check the initial ph of your water to make sure you do not buffer the ph if you don’t need to.

Your local aquarium store and even Amazon sell test kits that you can use to determine your tank’s ph level.

Now, a tablespoon of salt for every gallon of water will raise your water ph gradually and tip the reading enough if all you needed was a slight increase.

That said, you will note that most time, you won’t need to add baking soda (or any ph buffer) to your water. Most finnies will gradually adapt to a wide range of settings, more so species that have been kept in the hobby longer.

Below is a quick step-by-step guide on how to raise aquarium ph with baking soda.

  1. First, check your water parameter considering the fish you want to keep (or have). A ph kit, along with a testy for ammonia, nitrites, and nitrates, should not be too hard to find in your local fish store or even Amazon.
  2. Most fish do not need a strict ph, and they’ll be fine right where your water is unless you have extraordinary water parameters. So, the second thing you want to do is research your fish and how crucial ph is to keep them to make an informed decision.
  3. You may also need to check water buffering capacity since this is another reason you would want to add baking soda in your fish tank.
  4. To add baking soda to your fish tank, start with a tablespoon for every 5 gallons of water you have in your aquarium (0.2 to 0.5 salt per gallon). Give the tank a day, then test the ph.
  5. If after the first dosing, your tank’s ph is still too low, add a second dose of baking soda, then let it rest before testing your water. The gradual increase will make sure your fish don’t suffer ph shock.
  6. If at any point you note your fish is struggling after the change, you may need to stop or raise the ph much slower to keep them alive.

How Often Should You Put Baking Soda in Your Fish Tank

Baking soda is not an everyday fish tank product, so you do not need to use it frequently. As long you’re water hardness and ph is sufficient for the fish you have, you don’t need to use any at all.

The amount recommended in the paragraph above is pretty much standard, and you may only need to add a small amount of baking soda with substantial water changes likely to lower your water ph.

Moreover, if your replacement water is not too acidic or when using RO (reverse osmosis) water that needs to be remineralized, most times, there’ll be no need to add baking soda in an aquarium.

Will Baking Soda Hurt Your Fish

No, baking soda won’t hurt your fish, but as with everything under the sun, too much of it is harmful.

Only use an amount of baking soda that’ll serve the purpose you need it to, and not too much to stress your fish.

Why pH is Low in Your Fish Tank

The ph of your fish tank is most times determined by the source of your water. If you are your municipal supplies water with low ph, your fish tank will be acidic.

However, this is not the only reason your water ph reading can go low. Some aquarium decorations such as driftwood may release tanning in your tank, increasing your water acidity.

Sometimes, it might even be something you use in your fish tank, such as vinegar.

Even so, remember the effect of driftwood and vinegar (and what have you) will be gradual and needs to be in large amounts to bring down the ph in your fish tank significantly.

So, for the most part, you do not need to worry unless your water has low ph from the source.

What Happens If pH is Too Low in Your Fish Tank

The ph in your fish tank will affect different species of fish varyingly.

For instance, fish from hard, alkaline water Lakes such as Malawi cichlids will strain and most likely have a shorter (less than average) lifespan in low ph.

On the other hand, fishes native to dark, acidic water with tannins such as Tetras, cories, and other finnies from the Amazon river basin will thrive and remain content in your fish tank (with a low ph).

To cultivate an Amazon freshwater biotope tank, a ph anywhere from 6.3 to 7.3 with a general water hardness of 5 to 12 dh would be about right.

Blackwater Amazon streams fish like cories, loricariid, discus, and pike cichlids can even live in soft water with acidity as low as 4.5 to 6.5. But this range is stressful and borderline fatal to African cichlids.

So, to make sure your fish does not suffer ph shock from low (or high) than what they are accustomed to, research the fish you want to get.

Consider the ph of the water the species would generally live in in the wild, which also goes a long way if you want to companion your fish with similar finnies in a community tank.

Can You Use Baking Soda to Lower ph in Your Fish Tank

No, baking soda will not lower the ph of your fish tank. If anything, using a substantial amount will raise your tank’s alkalinity as opposed to increasing acidity.

Baking soda is an alkaline substance, which alters the effects of acidity in water.

If you are looking to lower the ph of your aquarium, the alternative would be to add a safe acidic substance like vinegar in your water.

Peat moss is a better alternative when looking for a natural way to lower your fish tank ph.

Thats all for this post, see you in the next one.

Happy fish keeping🐠🐟.

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