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How to Naturally Lower PH in Aquarium

How to Naturally Lower PH in Aquarium

Water PH is an essential parameter for hobbyists fond of keeping aquatic plants and tropical fish.

Both require the water they live in to be at a certain pH level to thrive. Too high or too low of a PH level causes stress in fish and plants, ultimately leading to their death.

How to Naturally Lower PH in Aquarium?

You can do this by simply using peat moss, bogwood, and Soil substrate. For further reduction, add RO water to the aquarium.

Hobbyists who keep soft water fish and aquatic plants face difficulty when their normal tap water is hard, which generally has a higher PH.

Lowering and softening the PH is essential to keep the fish and plants healthy.

Various Methods to Lower Aquarium PH

The different methods used for lowering the PH in aquariums have varying levels of effectiveness and consistency.

Some can be used using a combination such as RO & soil substrate, or Peat moss & bogwood is also an excellent way to go about it.

Before reading any further, it is essential to understand that each method’s efficiency depends on the type of tap water you are using.

The hardness of water that comes from the tap. 

German Hardness(dH)Water Condition
0-3Soft
3-6Moderately Hard
6-12Slightly hard
12-18Moderately hard
18-25Hard
25+Very Hard

# 1 Use Substrate to Naturally lower PH in Aquarium:

Using an originally acidic substrate with a pH level of 5.0-6.0 can lower the Ph and make it acidic.

ADA Amazonia is the best product available off the shelf (Link to Amazon). ADA Amazonia’s Ver.2 uses black soil as raw material, and it stands out against the leaf color of aquatic plants.

Anyone who is an avid aqua-scaper should not give a second thought to this product. Aquatic plants love this substrate.

Also, it makes the water quality suitable for aquatic plants and tropical fish. It is easy to maintain an aquarium initially to be used widely by beginners to veterans.

#2 Peat Moss:

The humic acid in Peat causes a decrease in water PH and is considered very well for plant growth.

For fish that prefer soft, acidic water (i.e., Amazonian cichlids, discus, and angelfish), a good quality peat moss enhances coloration and behavior in some fish species and promotes luscious live plant growth.

Peat Moss to naturally lower ph in aquarium

Peat moss has the property of filtering out minerals and release tannins, soften water and lowering the pH.

It lowers the PH very effectively through chelation, which is the process of absorbing cations, which are predominantly calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and heavy metals. These cations prevent the lowering of the PH value of the aquarium.

So once they are removed, the water gets softer, and you can lower the pH more easily. The moss also releases tannic acid, reducing the PH and resembling the waters of the Amazon and other rainforest rivers.

You can put the peat moss in a mesh bag placed inside the canister filter to do all the miracles.

Remeber that you have to replace the peat moss with fresh one based on the aquarium amount. Generally, a replacement is needed every 3-4 months.

As time passes, the peat moss begins to decompose, and its effect on lowering the PH and softening is reduced. The most straightforward measure often is the water turning back to its standard color. 

Always keep a test kit handy to test the water parameters, especially the water pH and KH. 

#3 Bogwood:

Like peat moss, bogwood and driftwood both have tannins which give the water brown tea-ish color.

Placing a bogwood adds beauty to the aquarium and helps lower the hardness and PH of the water.

Bogwood to naturally lower ph in aquarium

The leeched tannins, for some, add a natural Amazonian environment and look to the aquarium. The fish love this environment, not to mention the bogwood may not sink initially, so a stone can be tied to it using a nylon string to prevent it from popping up. The bogwood can also be boiled,

Although this may not qualify as a natural means but in my experience, using RO as a significant part of the aquarium volume tops the list. 

#4 Indian Almond Leaves (Catappa)

Although several leaves have can lower the PH, Almond leaves are the best, aka Catappa leaves.

Yet again, all these botanical solutions have more or less the same effect. These leaves also release tannins along with other essential elements.

The leave breaks down with time and produces Saponin Glycosides, a byproduct of the leaf’s decomposition.

Almond Leaves to naturally lower ph in aquarium

This also prevents fungal and bacterial infection. The elements released included iron, zinc, and copper, which are essential for aquatic plants and fish.

These leaves will have to replace based on the number of water changes made and, secondly, the hardness of the freshwater (tap water) added.

The more the hardness, the quicker the effectiveness of the leaves are rendered void.

#5 Alder cones

Alder Cones have also been in use for quite some time now. They can lower the pH of soft water rather quickly and add a brown tint to the water like other botanical methods. Additions will depend on the hardness of your water.

Alder cones to naturally lower ph in aquarium

Both Alder Cones and Cattpa leaves are the cheapest and easiest way to combat bacterial and fungal infections in fish eggs.

The environment is made healthier with either of these two options. Angelfish and Discus thrive in water with tannins and these priceless minerals.

To get the most consistent and long-term effects from each of the above-mentioned methods, I strongly recommend getting yourself a water treatment plant. 

RO Water:

Although costly, the quickest and most consistent fix to this problem is getting yourself an RO plant. You can work between 4~6 stages depending on the end PH demand.

Which species of Fish do best in Soft Water: 

Discus, Angelfish, Entire Tetra family, Barbs, and Corydoras catfish thrive in lower PH and soft water. Breeding these fish would be much easier than in hard water tanks.

Some hobbyists keep these in hard water, but the color and growth are much compromised in these water conditions as they contradict the type of natural environment for which these fish are built.