Freshwater

All About Substrates
Substrates come in many different shapes and sizes to suit the needs of each
type of aquarium. You can find substrates in grades from fine to coarse and in
different shapes such as smooth or chipped. The actual size of substrates can
often vary from vendor to vendor, so for the sake of this chapter, we’ll say that a
fine gravel is small like sand, a medium gravel is what is found in most prepackaged
bags at retail stores, and a coarse gravel is similar in size to a dime.
The substrate you put into your aquarium plays a very important role in its
overall biological cycle. In time, beneficial bacteria start growing on top of
and throughout the substrate bed and help break down waste in the aquarium
water. Substrate is also quite useful for anchoring live plants and for
holding down various types of artificial plants, live plants, and decorations.
Choosing the proper substrate gives you a good start on maintaining a
healthy aquatic system for your fish. So you’re probably wondering how to
find your way though this substrate mess. Well, read on.
Gravel
Chapter 5: What to Put and What Not to Put in Your Tank
Manufactured gravel is usually the best bet for a freshwater or brackish tank.
It is easily cleaned and widely available in pet stores and super centers by
the bag or the pound. Gravel also comes in many different colors and levels
of shininess. As you will learn, some gravels are better choices than others.
Most manufactured gravel is lime-free (so it doesn’t change the water chemistry
by raising the pH and hardening the aquarium water) and very inexpensive,
which makes it one of the most popular substrates.
Of course, gravel is a completely inanimate substance and does not provide
any type of nutrition for living aquarium plants. So, if you decide to use live
plants in your freshwater or brackish setup, you have to supply extra nutrition
for them by using plant plugs or liquid food. (Say what? Chapter 16
explains all that, we promise.)
Substrates and pH
Putting the right substrate in an aquarium setup is just as important as providing
the correct water conditions. One important point to remember is that
some substrates can affect the pH of your aquarium water, so make sure to
buy the correct type for the species that you own (check with your local
dealer on what substrate works best for the fish and plants you are going to
choose). Many live plants also have requirements in gravel size, so check
with your dealer to find out what is right for the species you plan on putting
in your tank. You will also find helpful setups at the end of this chapter.
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