A tank with substrate is a real beauty. With substrate, you can conceal the tank glass bottom with a natural material like sand or gravel. Add driftwood, a few rocks and some live plants if you like, then you have yourself a wonderful natural environment which will only enhance the beauty of your fishes.


For bichir keepers, having red colored substrate helps bring out the patterns of these prehistoric fish. Keeping a bichir in a bare tank with no background usually results in a pale colored and rather drab looking bichir. But transfer the same fish to a tank with red sand, and its true markings will soon be visible; the same fish will show its full beauty.

If you keep dark colored substrate in your tank, this will bring out a green hue in some species of bichirs like the Polypterus weeksii, P delhezi, P lapradei, and P palmas polli, just to name some, will bring out a green hue that you normally do not see in a bichir raised in a bare tank. I have no idea what causes them to develop a green color, but it is something I have observed in my many years of bichir keeping.

Having substrate will also help bring out the natural behaviors of fishes. For one, cichlids of the genus Geophagus will busy themselves sifting through the fine substrate looking for food to eat. They will do this all day and night, and your tank will never be boring with all the action going on. They are, after all, called the Eartheaters because of this unique behavior.

Stingrays are everyone’s favorite and are always on every fishkeeper’s list of fish to have. While it is very common to keep them in bare tanks, the more knowledgeable stingray keepers prefer to keep them in a tank with a fine substrate. This brings out their natural behavior of covering themselves up with sand with only their eyes showing. This is their hunting technique of hiding and blending with the surroundings to improve their chances of a successful hunt. When they bury themselves in fine sand, would-be prey have no idea that a highly successful predator is just beneath it, ready to lunge. Stingrays lie motionless most of the time, and they find peace and solace at the sandy bottom.

But keeping substrate has its own challenges. The concern is mostly associated with cleaning the substrate before using it and while having it in your tank. To be totally honest, it is a bane to clean substrate and keep it clean. So, is having substrate in your tank really worth the effort?

The substrate available to fishkeepers for their aquariums is generally sand, or tiny bits of rocks collected along riverbeds or the sea. In some cases, the latter are man-made from rocks that have been ground to tiny proportions, fit for aquarium use. Whether it is natural or man-made, it is generally dirty, no matter how good looking the packaging is. The worst thing you can do is immediately pour the sand you have just purchased in your tank without even cleaning it. You will absolutely pollute the water in the tank.


So the very first step is to wash your sand. Washing is nothing more than rinsing the newly purchased sand. Get a basin, and put the sand in it. Fill it up with water. Stir it up a bit. Remove the water by emptying the basin, and repeat the process. Really a very simple process, like rinsing rice before cooking. But it just takes longer, so much longer—in fact, it can take so long that you actually tire out and get body aches all over so that you cannot even just stand up. This is a killer task for your back, not only for fishkeepers my age but even for those half my age.

Washing your sand is a tough job. Fishkeeper Gino Daus, who had just started out in fishkeeping, bought two sacks of red garnet sand for his tank. “I divided it into four parts per sack because it would be too heavy if I cleaned the whole sack,” says Gino. “I must have cleaned it 5 or 6 times for every quarter of a sack.” Doing the math suggests that he would have rinsed the sand 40 to 48 times. But he confesses, “Yet it (referring to the water used to rinse the sand) is still slightly cloudy.”

Considering that garnet sand is man-made sand, it is generally clean compared to collected natural sand, where all sorts of natural debris can be found, like twigs, rocks, shells, leaves, and dirt. Oftentimes, man-made stuff like plastics, candy wrappers, glass, and the like are also present. These things often present themselves on your first few rinses and are hard to get rid of. It will take so much more rinsing to remove all these—unless you want to pick them off one by one; in some cases, this is your only choice.


One of the most popular kinds of sand used in fishkeeping is white sand. In fact, from the time I began keeping fish, white sand had always been the choice for aquarium substrate. White sand is natural sand collected from the sea, and in our country, we have many seasides, something we are proud of. White sand is actually composed of the skeletons of corals broken down by nature into tiny particles, by parrotfishes nibbling on the corals, or erosion by the sea.

Since white sand comes from corals, it is naturally rich in calcium. This is a highly desirable quality which African cichlid keepers prefer, since cichlids from the Rift Valley Lakes in East Africa like Lakes Tanganyika, Malawi, and Victoria have water with high Ph and high water hardness. Therefore, African cichlid keepers are well advised that their tanks benefit a lot from having white sand. Dennis Chan has been a cichlid keeper since the early 1990s and he confesses he practices the use of white sand in his African cichlids tank. “Ever since I collected cichlids from Lake Malawi and Lake Tanganyika, I have been using white sand in my tanks.” This of course is for good reasons.

However, calcium mixes with the water, giving it a white milky color. When washing white sand, it is a common experience that it is so much more difficult to clean compared to other inert kinds of sand like red garnet sand. The more you rinse white sand, the milkier the water becomes.

Thing is, in your haste to clean white sand, the more vigorously you will stir the water. This only makes matters worse, and after some time, you will be frustrated and give up on washing your white sand. Dennis shares, “When I first used white sand for my African cichlids, I was so obsessed in cleaning the white sand that it (took) me the whole day rinsing it. By the time I (got tired and gave up), that’s when I observed the water in the basin cleared up. I found out that you will never get to clean white sand completely because calcium makes water milky. Nowadays, after a few rinses to remove the debris, I put the white sand in the tank. I do not worry about the milky water; I just turn on my filter and let it clear up the water.”

If the initial washing of aquarium sand is difficult enough, just how dirty do you think your sand will be after your fish mess it up? Of course the sand in your aquarium will become dirtier and dirtier as time goes by.


The common way to keep things clean is to use a siphon to rid the tank off debris. The process is simple. Get a hose and start a siphon. With the tip of the hose, remove the solid wastes embedded in the sand. Be careful not to siphon off the sand because you do not want sand scattered everywhere you dump the water. Worse, you don’t want sand clogging your sink or sewer lines. This may not be an efficient way of cleaning your sand, but it gets the job done.

Some fishkeepers even remove all the driftwood, rocks, and décor because these are places where dirt collects. For Ace Resultan, this is his practice before siphoning off debris. “I have to remove the driftwood and rocks or whatever decoration I have so I can fully clean my tank. But somehow I am never sure if I fully cleaned my tank.”

A more effective way is to use a gravel cleaner. This is a marvelous gadget. It is simply a hose with a wide nozzle. Simply start siphoning. Ram the nozzle through the sand. You will observe that the sand will be sucked up. But since the nozzle is wide, the heavier sand will fall back while the dirt will be sucked off and exit through the hose. After removing 30% of the water, top it off with tap water. Not only have you cleaned your sand, you have likewise just made a 30% water change.

Ultimately, in deciding whether to have substrate in your tank or to simply keep a bare tank, it is best to look at your lifestyle. If you are a busy person and cannot devote much time to cleaning and maintaining your tank, then it is best to go bare tank. But if you are a devoted fishkeeper who will find joy in cleaning and tinkering about in your tank, then a tank with substrate will be more rewarding. It is not going to be easy, but the best things in life are those you worked hard for.


This appeared in Animal Scene magazine’s May 2017 issue.