Before you decide to use sand in your new fish tank, you need to learn a little more about it.
Why choose sand?
Well, sand is great for live plants. They’ll root very nicely in it. Sand doesn’t shift as gravel does and the plants will not get loose.
Some fish – such as Eels – like to bury themselves, so sand is a great option if you have fish like that.
Sand can give your aquarium a tropical look.
Let’s begin with the different types of sand you can choose from:
A lot of people use play sand or silver sand, fine white sand used in gardening. Play sand is cheap. However, it might create excessive algae growth in the tank
This is what we know as pool filter sand. Some people say it stays better on the bottom. This is the one I recommend.
This is typically silica sand that can be artificially colored. Aquarium sand is just a little thicker than silver sand but it costs a lot more.
Marine sand is usually made up of crushed corals or crushed seashells, and this kind of substrate will alter the pH of your aquarium, and it’s really not recommended for most tropical fish. However, marine sand is suitable for fish that require high pH such as African cichlids. Do not use it for freshwater setups!
The sand you can freely find on a beach contains a huge amount of salt in it and it’s almost impossible to get rid of it completely. You could use beach sand for marine setups but remember that many beaches are polluted in some way and that could end up being very damaging to your aquarium. So unless you can get it from a pristine beach in the middle of the ocean, I wouldn’t recommend it.
Never use building sand in your aquarium since it might have chemicals added to it to help with creating mortars.
Whatever sand you use, make sure you read the labels to check for added chemicals. Some brand of sand sold in big home improvement stores comes sterilized and totally inert.
How much sand do I need?
If you have live plants, I would cover the bottom with a minimum depth of 1″ and a maximum of 1.5″ of sand. If you don’t have live plants 1″ or less will be perfect. If you put over 1.5″ you can cause anaerobic bacteria to build up in pockets and create toxic gasses like methane and high levels of CO2, which might be deadly to your aquatic life. To avoid this, stir the sand a couple of times a week. You can use your fingers gently, or a very thin object, always watching out for the roots of your plants. You can always add some critters to keep your sand free
of uneaten food. You can have scavengers such as a sea cucumber.
What kind of filter do you need?
A UGF will not do. In just a few days the filter will become useless. A canister filter is safe, as long as the filter intake is at least 1″ above the sand. In any case, you have to use a very good filter, maybe one stronger than the one required for your tank capacity, at least 3 times the power.
You must turn off the filter on your tank when you first start to use the sand. It always starts very cloudy and you have to give it time to settle.
Keep in mind that sand might be a little tricky to clean. Always maintain the siphon at least one inch over the sand. Once you get the hang of it, it should be very easy, since the debris does not get buried in the sand as it does in gravel. Now, since the debris does not get buried, it’s much more visible, but with the right setup of filters and pumps or powerheads, you can have all the waste get pushed away behind a rock or back in a corner.
Once you get your sand, make sure you rinse it thoroughly until the water comes out clear.
Also, do some research to decide what fish will thrive with a sand substrate and which won’t do as well.
Sand can be used in salt and some freshwater tanks. Don’t use sand with Goldfish, for example, because they will just grab mouthfuls of it when looking for food, and obviously, that’s not good for them.
Some sands, like marine sand, can change the PH in the water, so make sure the change your particular will create will not be harmful to the fish you want to keep. You can get away with coral sand in an African cichlid tank because coral sand will raise the pH naturally and freshwater African cichlids actually like that.
Setting up a new tank with sand is easy if you follow the precautions about the filter, the siphoning technique and you research the kind of fish you want. But it’s also possible to convert from gravel to sand in an already established tank, it’s only a little bit more complicated since you have to take out plants, decorations, and fish to do it, but once done, your tank will look so beautiful you will forget all about the hard work.