Sand vs Gravel vs Bare Bottom. What is Better for Shrimp and Fish?

pile of sand and gravel

Today I would like to talk about bare-bottom tanks, sand, and gravel as a substrate. We are going to look at the advantages and disadvantages of sand and gravel for our shrimp and fish. We will try to find the answer to whether the substrate is even required. I will give you the list of pros and cons for every case.

So without further ado, let us get right into it.

The first thing people usually start to think about, after buying a new aquarium, – is what are they going to put in there. Should it be sand, gravel, or some specially created substrate? But do they really need it? Is it possible to decorate the aquarium and make it look natural without any substrate? What are the advantages and disadvantages of having and not having substrate in your tank at all?

Let’s start with No Substrate (BBT – Bare Bottom Tank)


  1. The main advantage will be the simplicity of maintenance. It is really easy to clean. You can take gravel siphon and eliminate all the shrimp or fish waste very quickly.
  2. Easier to maintain water chemistry at a certain level. The substrate can increase or decrease water chemistry in a tank. Any aquarist will tell that. It is a never-ending battle to keep it balanced if you have any substrate in the tank.
  3. It does not cost you anything.
  4. Bare bottom tanks are really good as Quarantine” for the plants, sick (new) shrimp, or fish. If any parasites do come in with them they cannot burrow down in the substrate and live there. Also, if you are a fish keeper it is the best option for breeding. If you are a shrimp breeder, it is the best option for culling shrimp and selective breeding.
  5. There are no unexpected guests in the bare-bottom tanks. For example, bristle worms can be real troublemakers in saltwater tanks and flatworms (planaria) can make shrimp keepers cry in freshwater tanks as well.


  1. It does not look natural and a lot of people really dislike it, when the tank is almost empty.
  2. Another point that I could add is that if you leave the tank for a couple of days you will have complete chaos made of the fish or shrimp waste and all the uneaten food.
  3. On top of that, I can also add that your fish and shrimp will be very unhappy as well. There are some types of fish, which enjoy interacting with the substrate. Some of them like to bury in search of food, others use it as camouflage or as a place to hide because the substrate plays a vital role in the underwater world. As for the shrimp, well they need to have something to grip on, actually.
  4. We should not forget to mention that if you eventually decide to keep plants in a tank, it will be a good challenge. Because you may have to use potted plants or maybe you have to tie plans (like Java fern, Anubius) to driftwood or rocks. Of course, in case of success, your tank can be just as beautiful as any other planted tank but it will take you significantly more time and effort.
  5. Unfortunately, without substrate, you will also get rid of the good critters like copepods and amphipods that can be a natural source of food for some fish.
  6. Another downside is that there is no biological filtration. It means that you will have to do water changes more often to control ammonia

Shrimp or Fish Tank with Substrate

The substrate in a tank changes the whole picture. It makes it look significantly more satisfying.

The other advantage of having some type of substrate in the tank is the fact that the substrate provides more surface area. It means that this surface area in the tank is going to allow you to grow more microbes. Those microbes will allow you to get rid of ammonia and nitrites. Also gravel and sand allow a lot of surface area to grow those microbes.

A second feature that we should mention is that if you have got gravel or sand in the tank it can hide to some point the fish and shrimp waste. So when you are done cleaning a couple of days later it does not look like a mess again.

Gravel in the Tank

Time is changing and what was good yesterday is outdated today. This is what is happening with gravel and sand nowadays. They have been pushed out by hi-tech substrates in many tanks.  You can read more about “Top 5 Substrates For Planted Aquariums” right here.

Nevertheless, there are a lot of old-school people who still prefer natural substrates, although it can mean they will have to rinse, clean, disinfect and test it for unwanted chemical elements before putting in the tank.


  1. The good thing about gravel is that it can look nice and you can get different colors and different shapes of gravel that suit your needs. You have basically a limitless choice of variants.
  2. Your baby shrimps will love to hide between grains. That is why it is excellent for their safety.
  3. As was mentioned before, it also does a really good job of hiding the wastes until you can do your cleaning in the tank. So your aquarium will look very nice for a long time.
  4. A further positive aspect of gravel is that some plants will have better chances to anchor to the surface. Gravel is great for column feeder plants.
  5. It can be also a good biological filter as well, unlike BBT. Because it will provide a large surface area for the beneficial bacteria.
  6. There is no problem with cloudy water; on the contrary, it keeps the water clean.
  7. It is easier to vacuum through the gravel to get the entire gunk.


  1. Unfortunately, the fact that gravel can hide the waste can also have a negative moment. If your gravel is too big, in this case, uneaten food tends to get trapped in that gravel a lot sooner than gravel that is a smaller size. As a result, it is easier to clean the tank which is filled with small gravel.
  2. The second downside is that compared to a bare bottom tank you will have to spend some money to buy it (lucky us it is relatively cheap 1-2$ per 1 lb.).
  3. In addition to this, you need to know what type of fish you are going to have because some fish (like Loach, Cory catfish) may prefer others If you have fish that spends a lot of time on the bottom or fish that is very sensitive in general, larger gravel might not be a good choice. For example, there have been many cases of fish cutting themselves up on the gravel and which can eventually lead to death. Also, fish like Discus or Catfish (they are quite offensive) could easily get scratched up by the sharp edges of the gravel. Just keep it in mind and make sure to use only smooth gravel.
  4. Algae can spread very fast on gravel.
  5. There is always a danger to squash the baby shrimp in the gravel while cleaning.

Hint: it’s recommended to get one or two pounds of gravel per gallon of the fish tank.

Sand in the Tank

 Although gravel has lots of benefits, sand can suit really well for some setups. Sand has some good things about it as well.


  1. There is nothing that looks more natural than sand.
  2. There are no cracks for food to get lost and although it seems to get dirtier faster, actually, it just keeps the dirt on top rather than covering it.
  3. It is the cheapest compared to other substrates (1$ per 5lbs).
  4. As well as this, you can also get different colors of sand.
  5. It can be sifted and easily moved around by fish with no injuries. Many fish like to interact with the sand.
  6. In addition, some of your plants will grow just fine in the sand. For substrate-rooted plants (like Cryptocoryne Wendtii, Aponogetonulvaceus, Vallisneria and etc.) depth is crucial. You need enough depth (2-3 inches) to provide a rooting medium. If you are not going to have rooted plants, there is no reason to have a depth of more than 1 inch.


  1. First of all, it usually cannot be a biological filter as the particles beneath the surface of the sand are suffocated and deprived of oxygen and therefore cannot host aerobic bacteria. If you have got a lot of sand packed up it may begin to trap hydrogen sulfide gas (creating toxic gas pockets) and it can harm and kill your shrimp and fish. In order to avoid this problem, your sand grain size should be at least 0,02-0,04 inches (or 0,5-1 mm). (adding iron supplements can help to control the hydrogen sulfide (H2S)). Another way is to move (rake) it during water changes.
  2. You have to clean and rinse it first very thoroughly before putting it in the tank. When you think that it is clean enough, clean it some more.
  3. Some types of sand can change the chemical composition of the aquatic environment.
  4. Another disadvantage is that some plants do not root well in sand.
  5. Sand does not have enough nutrients for vegetation, therefore fertilizing is required.
  6. Sand grains can damage the glass of the tank while cleaning if some grains are stuck on your scrubber.
  7. The last disadvantage is the fact that it shows shrimp and fish waste far more quickly than gravel. It gets dirtier faster and takes more work to make the tank look perfect all the time.

 Hint: if you are going to get sand and do not want to spend much money, stick with the pool filter sand (or take a look at Estes Marine Sand) as opposed to the play sand. It is a much finer grain it packs more tightly and it’s a little bit harder to clean.


It really does not matter much what you will choose. Your shrimp will be happy in anything, especially if you add some plants to your tank.

Everything just comes to maintenance and with sand, it can be a little bit simpler. Nonetheless, it should not dissuade you if you want to try gravel. Because it is a good biological filter and you will never be worried about gas pockets. 

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Content