There is a long-standing debate between pond owners about whether or not to have rocks in your pond. On one side you will find the group who argue that having rocks and gravel on the bottom of a pond will harm the fish and cause poor water quality.
The other side says that rocks and gravel are fine and in fact will help house good bacteria as well as creates a more natural Aquascape.
Both can be very firm in what they believe. Below I’ll share Damascus Enterprises’ opinion on both sides.
Rock Bottom Pond
Rocks used in ponds provide the following benefits:
- Adding rocks allows the aerobic bacteria (beneficial bacteria) in your pond a place to colonize and start filtering out debris like fish waste and plant debris. Aerobic bacteria need the presence of ammonia and oxygen in your pond. Ammonia is produced by fish waste and decaying plant material. The oxygen needs to be continuously supplied to your pond in order to keep the beneficial bacteria active.
To encourage this healthy balance, we suggest you run your pond pump 24 hours a day to be sure the water is continually being oxygenated. For added benefit a dose of beneficial bacteria can be added weekly to your pond, we recommend using Aquascape Beneficial Bacteria. - Believe it or not rocks and gravel help to protect your liner from UV light degradation and extends the lifetime of the liner membrane. Over time UV light can begin to break down your liner, making it less durable and more susceptible to leaks. By blocking the UV light you can get many more years out of a high-quality pond liner.
- By adding rocks to your pond it adds a more natural look to it; as if mother nature put it there herself. Adding rocks can be used as an opportunity to help protect your fish by including fish caves for them to hide in if/when a predator comes along looking for a meal.
Disadvantages of a rock bottom pond include:
- Like any pond, if it is left to sit without maintenance for years on end it may become too toxic for fish life.
- The build cost is higher due to the cost of rocks and gravel.
Bare Liner Pond
There are also benefits to keeping the liner rock free in your pond. Without rocks or gravel in your pond tasks like vacuuming or water changes will be a lot easier, eliminating the nooks and crevices for organic materials to settle. No rocks can also mean it’s easier to maintain proper nutrients for more delicate fish and marine life.
Benefits of having a bare liner:
- A bare liner will allow you to vacuum the pond on a regular basis. Without the rocks in the bottom, cleaning/vacuuming the bottom of your pond will be a lot easier. Bare liner ponds used by fish enthusiasts typically have a bottom drain which will make draining and cleaning easier when done more often.
- Simulates more of an aquarium like environment to help maintain a more exact habitat for your fish, especially with more sensitive species.
Disadvantages of a bare liner:
- Creates an unnatural looking pond, like an outdoor aquarium.
- Any debris that falls to the bottom is not consumed by heterotrophic (beneficial) bacteria where it accumulates and needs to be addressed.
- Leaves no protection to the liner from harmful UV rays that will break down your liner over time.
- No plants used, no balanced eco-system.
In Our Opinion
We have found, when built and maintained correctly, a natural ecosystem pond that includes gravel and rocks is in no way unhealthy for fish. We have many customers who have gravel and rocks in their ponds along with some great looking Koi and other fish, and the fish have been doing very well for many years.
Ponds require maintenance regardless of the type. So, if you have some prize fish that are extremely expensive and mean the world to you, a bare liner pond may be the best option, but you might also be putting more time and/or money into it.
A pond that has gravel and rocks instead of a bare liner, when done correctly, should look like mother nature built it herself. These ponds, ecosystem ponds, rely on the balance between plants, fish, bacteria, and filtration to stay healthy and beautiful, and it works!
Having a beautiful natural looking ecosystem pond in your backyard will create a relaxing paradise where you can unwind and enjoy the pond life.
Choosing between rocks or no rocks in your pond boils down to personal preference, what you will mainly be using your pond for, and the amount of maintenance you are committed to providing.
We will be more than happy to discuss options and help point you in the right direction in designing or renovating your water feature.
