Why use oyster shells in a pond or basin?

There must have been a time when you noticed oyster shells in some ponds. Apart from the aesthetics they provide, these shells play an active role in the pond's ecosystem. And for good reason, they are excellent factors for stabilizing the carbonate hardness (KH) and the total hardness (GH) of the water.

We tend to think that if the water they take from the tap is harder, it shouldn't cause problems for the KH and pH of the water. Since KH works much like a buffer of water acidity (pH), it's always a good idea to test water parameters before jumping to conclusions.

⭐ It may interest you: we wrote an article to help you analyze your pool

Carbonate hardness (KH): an important but often overlooked value

Fish, plants and the biological filter "consume" the hardness of the water (KH). If the water is not changed enough during the winter, for example, the KH can quickly drop. This also happens during rainy periods. By extension, this kind of variation can have big consequences for fish. Indeed, in these situations, the pH of the pool can drop suddenly.

The KH is not measured regularly enough in the basins. Only in case of problems, and therefore when it is already too late, we try to remedy the situation by adding, for example, KH+ powder. However, this powder has a number of disadvantages:

• a lot of powder disappears in your filtration system (backwash)
• a boosted effect only in the short term,
• large fluctuations in water values
• If it rains, you have to put on KH+
• you have to constantly measure and add powder

How to stabilize the GH and KH hardness of the pool?

In detail, you can quite easily regulate the total and partial hardness of the water. Depending on the situation, we will choose to use products or move towards other alternatives. In this case, to stabilize the GH and KH of the basin, you can use Optiminera or apply a more natural solution such as oyster shells .

Optiminera: the minerals proposed by Aquatic Science

Optiminera products are suitable for those who want to clarify the water, accelerate the reduction of silt or reduce the rate of phosphates. They are therefore natural minerals, perfectly suited to optimize pH and hardness over the long term.

In parallel, as it contributes to the stabilization of the pelvis, Optiminera also helps in the prevention of diseases. In practice, the Optiminera minerals are to be distributed on the surface of the pond. We will focus particularly on places where there is good circulation of water.

There are super practical packs like the Ichi Pond Starter Kit , which allow you to have everything you need at your fingertips. In other words, this starter kit includes:

• food for koi carp
• of the Optiminera
• of the Optinit
• Biobooster _
• Bactogen

Oyster shells: a natural and long-term solution

Beyond their taste value, oysters can still play a big role for the pond. We are talking more exactly about oyster shells, which are able to ensure the regulation of the KH and the pH of a basin. In detail, these shells dissolve only when the KH value drops. At this time, they act as a buffer on the pH (the acidity level of the water).

They absolutely do not depend on the amount of rain, the change of water or the seasons: oyster shells ensure a stable level of KH and pH values ​​of the water. Only, when the oyster shells are practically dissolved, it is necessary to add others.

As an indication: one bag of oyster shells per year for a volume of 10 m 3 will suffice. Of course, the amount needed naturally depends on the factors described above.

Oyster shells are generally used in waters that are too soft, so as to increase the carbonate hardness. At the same time, the shells are also suitable for use as biological filter material. They can therefore be installed in a drip system or in a multi-chamber system.

The oyster shells offered on FouDeBassin.com are washed with chlorine and then dried. In particular, this is a guarantee that harmful bacteria, fungi and other germs are effectively eliminated. Finally, the oysters are delivered in a net, which can easily be rinsed if necessary.

The advantages and disadvantages of soft water

Soft water is not absolutely good or bad. This will mainly depend on the use you intend to make of it. Of course, the hardness of the water will have an impact on the ecosystem: fish like vegetation will develop differently.

⭐ You may also be interested: our article that helps you choose which water to use for your fish

What are the benefits of soft water?

• Promotes the growth and development of the red complexion of koi carp
• Limits the accumulation of ammonia.

What are the disadvantages of soft water?

• For koi carp: a less clear white complexion and black evolves less well.
• Fish osmoregulation needs to be more efficient
• Promotes the development of unwanted algae.

How to increase carbonate hardness?

• Added harder water.
• Addition of limestone, in the form of stones or shells