If you’re just dipping your toes in the aquarium hobby, then it’s not long before you encounter hobbyists who will die by gravel or sand. Each party will give you a multitude of reasons as to why you couldn’t possibly be successful with the opposer. This limited thinking excludes the benefits that sand and gravel can offer. It may be true that these substrate extremists are correct, but that does not mean the other is wrong. Certain substrates simply work better depending on what type of tank you're running.

Why Substrate is Important

Aquarium substrate does more than make your aquarium look aesthetically pleasing. Substrate mimics fish’s natural environment while alleviating stress on the glass. The bacteria contained in substrate benefits the nitrogen cycle, which promotes healthy plants, fish, and water by reducing nitrates. There are endless ways to customize your substrate to your needs, such as aqua-soil, peat, sand, gravel, clay, laterite, and many more.

Sand

Sand is a common choice for those wanting a smooth, natural floor to their aquarium. Sand stays around the same price as gravel, with higher quality sands costing more. Depending on what fish and plants you keep, sand may be the right substrate for you.

Benefits of Sand as Substrate 

A majority of fish naturally live in sandy environments and will help maintain the sands cleanliness by digging into and sifting through it. Sand sifters are not only beautiful fish, but clean your sand by sifting out algae, detritus, and food. These fish tend to create slopes and holes that are more natural in appearance when compared to gravel.

Sand can be extremely fine or coarse, but stays uniform in shape without any coarse edges that could be harmful. Sand has more neutral color options than gravel and can easily secure decor and large objects. 

Due to sand being very fine and consistent, debris lays on top allowing for an easy clean up. Debris is not able to sink between gaps and crevices and cause a buildup of bacteria. Your filter will move the debris around and clear it out quickly, and whatever is left from sifters and filters can carefully be vacuumed out. 

Negatives of Sand and Substrate 

Sand can appear dirty and messy if not regularly maintained, which can be unappealing to some hobbyists. This can be controversial because while gravel may conceal debris more, it is still there and affecting water parameters. This dilemma differs from person to person.

Sand’s small size restricts water movement, so proper filtration and water movement is vital due to dead zones. Sand’s size also affects plants ability to gain nutrients through their roots and properly burrow without being compacted. You will be limited to what type of plants you can keep in a planted tank unless the roots stay out of the substrate.

Important to Note

Choosing a quality aquarium sand is vital to your tanks success. Pool and construction sands are unsafe and unsuitable for aquariums. Luckily, quality sands are available at most pet stores.

Gravel Substrate 

Gravel is the most common choice for new hobbyists and freshwater. Gravel has the most variation in size, color, and structure. Gravel allows water flow, which prevents the buildup of bacteria, amoebas, and mold which promotes the nitrogen cycle. 

Plants tend to thrive in gravel due to their ability to root and gain nutrients through the water. Bacteria thrives in this substrate, allowing for plants to have a substantial source of food.

Many freshwater fish and invertebrates naturally live in gravel environments, and will enjoy hiding under rocks and picking at algae in the substrate.

Negatives of Gravel as Substrate 

While gravel hides algae better than sand, this can be problematic if not maintained. Algae has more of an opportunity to flourish in gravel, which can cause more frequent outbreaks and be more difficult to eradicate. Frequent water changes and vacuuming can help maintain algae.

Depending on the composition of the gravel, the stones can rip into fins and scales. Fish may try to eat the gravel or accidentally consume some while picking at bacteria, creating a choking hazard and possibly upping sickness and mortality rates.

Conclusion 

Advocates for sand and gravel both have their reasons for their choice, but it is undeniable that these substrates have pros and cons depending on what type of aquarium they are placed in and how often the owner wants to maintain it. Pick what substrate works for you and have fun creating the tank of your dreams!