When starting off your fish tank, one of the first decisions that you have to make is what kind of substrate you want to use. There are three common options that all have varieties to them. There is a gravel substrate, sand substrate, and a bare bottom substrate.
The most common choice for freshwater aquariums is a gravel substrate. Gravel substrates comes in a lot of different shapes and colors. There are plenty of colored choices you can find at any pet store to match a specific theme. There are also dark and natural looking gravel that you can have in your tank if that is the look you desire. The positives of having gravel in your tank is that it is generally the best substrate to really anchor plant roots down. A lot of plants aren’t able to move their roots through the substrate. Since the sand is really compact, it also makes it harder for the roots to absorb nutrients in it. However, with gravel, there is some water flow that allows the plants to take in all the waste in the bottom layer. Gravel is also the best substrate for making the tank look clean. With sand or a bare bottom tank, waste just piles up and looks really off putting. With gravel however, the waste falls into the little cracks and gets out of sight.
The next most common substrate is any kind of sand. You can get basic play sand for a tank, or pay a lot of money for some higher quality sand. Sand is used in tanks mainly for its looks. Nothing looks more natural to many than a sandy tank bottom. There are some species that like to bury in the substrate, like eels or cory catfish, and they should be kept in sand tanks. If you have a species that burrows, it will hurt itself in a gravel tank because they instinctively will still try to dig around in it. Sand tanks can be rather difficult to clean. Unlike gravel tanks, you can’t just stab a siphon into it and have that pick up all the waste. Since the sand is so light, it will also be sucked up with the water and after a few cleanings, you will have barely any substrate left. The sand lets all of the waste settle on top of it, which makes it look unpleasant if it is not cared for properly. The biggest hardship you can have with sand is that it can easily clog your filter. You should be careful not to have you filter intake too close to the bottom of the tank. Doing this will result in sand being sucked up and that could destroy your nice filter.
Bare Bottom tanks means that there is no substrate used. This is not routine in community tanks. Instead, it is common to see in breeding tanks, or in hospital tanks. It isn’t done normally because none of the waste gets hidden. It isn’t a natural look and isn’t enjoyable to look at. It is often used in nursery tanks because it lets you see all of the babies in the tank. It also requires very little work to set up if you have a cycled filter, so that is why they are used in hospital tanks.
So what will you choose to do for your tank?