If you’re new to pond keeping, then you might be wondering what all this stuff about “pond substrate” is. Well, let’s start from the beginning.
Pond substrate is the name given to any natural material that you put onto the bottom of your pond. It’s basically the pond keeping equivalent of potting soil. It’s the stuff that your plants grow in, and it’s what’s going to actually give your pond its natural look.
Now, pond substrate is optional, but I wouldn’t advise against using it. I mean, you do want your pond to look natural, right? Pond substrate is also a great way to keep the water from going murky, since it provides a place for the biological filtration to occur. I’ll explain more about that later.
So, to answer the question of whether you need pond substrate or not, the answer is no. You don’t need it. It’s just that if you don’t use it, your pond won’t look as natural, and you’re going to have to rely on other methods of filtration to keep your water clear.
That’s what pond substrate does, you see. It acts as a natural filter that prevents the water from going murky. That’s why if you’re not going to use pond substrate, then you’re going to need to rely on a mechanical filter instead.
You’ll Need a Mechanical Filter
If you’re planning on not using pond substrate, then you’ll need to use a mechanical filter instead.
Mechanical filters are the only way to prevent your water from going murky without using pond substrate. They work by physically removing particles from the water that would otherwise make it look dirty.
I bet you’re thinking “well, why don’t I use a mechanical filter and pond substrate at the same time then?”
You can if you want, but it’s not necessary. Pond substrate is a great way to keep the water clear without having to rely on a mechanical filter, and it also provides a whole bunch of other benefits as well.
The Benefits of Pond Substrate
Okay, so let’s say you’ve decided to use pond substrate. Here’s what you’ll get out of it.
First of all, your plants will grow much better.
That’s because the substrate provides them with a solid base to anchor themselves in. With sand, for example, your plants will just fall over without much resistance from the substrate. With gravel, on the other hand, they’ll be held up just fine.
Gravel is one of the best substrates you can use if you’re looking to grow pond plants, by the way. It provides a nice, stable base, and it has enough room between the pieces for the plants’ roots to spread out.
If you’re looking to grow water lilies, then you’ll want to use a layer of clay or topsoil underneath your gravel, since they’re heavy feeders.
Secondly, pond substrate acts as a natural filter.
As I mentioned earlier, pond substrate is a great way to keep the water clear without having to use a mechanical filter.
That’s because the substrate provides a place for the beneficial bacteria to grow that will filter the water for you. This is called the nitrogen cycle.
You see, fish produce ammonia as a waste product, and ammonia is toxic to them. Ammonia is also the first stage of the nitrogen cycle.
Beneficial bacteria that live in the water will convert the ammonia into nitrite, which is the second stage of the nitrogen cycle.
Nitrite is also toxic to fish, but don’t worry, because there are beneficial bacteria that will convert the nitrite into nitrate, which is the third and final stage of the nitrogen cycle.
Nitrate is not toxic to fish, but it can cause algae blooms if there’s too much of it. That’s why it’s a good idea to have some aquatic plants growing in your pond to soak up the nitrate and prevent an algae bloom.
By giving your beneficial bacteria more surface area to grow by using pond substrate, your pond will be able to handle more fish, and the water will stay clear.
Finally, pond substrate will give your pond a natural look.
If you’re not using pond substrate, then there’s not much else you can do to get your pond to look natural, apart from getting a few rocks and stones to put in the bottom.
As you can imagine, this is going to be a ton of work if you have a large pond, and it won’t look as good either.
With pond substrate, on the other hand, you can get the natural look much more easily and effectively. I mean, you’ll still have to do a bit of work, but it’ll be worth it.
