This is a great question that seemingly has not been addressed often online. I know because I looked it up when I started preparing this article.
That in itself is strange given how often I’ve heard it asked before. It’s natural that people would be asking themselves this question. One begs to wonder why it’s rarely brought up online.
Is colored aquarium gravel safe? Yes, Most aquarium gravels on the market are created from safe no leech plastics and natural stones or coated with polymer seal.
Why is this important? The problem starts with the dye coating used on gravel. This can leech into the water of the fish tank and do all sorts of damage to its inhabitants. It can also be so strong that it completely changes the color of the water.
So it’s important that you use natural stones, Special no leech plastics or gravel that has been coated in a thick polymer seal.
You can apply polymer seal yourself at home with relative ease if you have access to silicone sprays. This is an expensive and time-consuming route to go down though. It involves a lot of cleaning and take care not to miss any spots on your aquarium pebbles.
Is colored gravel bad for fish?
In an of itself no. The big offender is the dye or other chemicals leaching from the substrate. When you buy reputable brands then you will not run into these issues at all.
Given there are so many brands that are good, I won’t name any of them to make sure I’m not playing favorites.
Finding the right, good quality brand is easy. On Amazon or most retailers, they are often the most purchased and highest reviewed.
What color gravel is best for fish tank?
This is a fascinating question because it can go much further in topic than just color.
While it’s not uncommon for pet fish to become accustomed to colorful artificial gravel, it has been noted that fish prefer a more natural environment. Such as keeping the same color, shape, and general size of the substrate. Here are a few of the most common pet fish and their natural habitats.
Gold Fish (Cyprinidae family)
Goldfish are super common, not just in our homes and aquariums but in nature as well. Rather ubiquitous, they are at home in just about any stream, river, pond, lake, man-made reservoir in almost every temperate and tropical zone.
We’ve certainly had our hand in this in the various way’s humans dispose of unwanted goldfish. Unfortunately.
Recommended gravel type: smooth, rounded, sealed*
Recommended colour: Any
*Goldfish like to swallow their substrate as well as get up close to it. So you should avoid such things as abrasive rocks (lava stone, tufa, etc). You should also avoid crushed or jagged glass. These things will hurt your goldfish.
Beta Fish (Betta splendens)
Beta’s natural habitat is slow-moving streams and flooded rice fields. They come from Asia primarily. [source] The gravel for betta should be:
Recommended gravel type: Natural Pebbles
Recommended colour: Brown/natural with hint’s of green (grass colored)
I personally believe beta fish feel best at home in a natural pebble based substrate. You have the option to choose more artificial colors, of course, this shouldn’t affect the beta fish that much. Keep in mind that if you keep a darker more natural colored gravel your fish’s color will pop out more vividly.
Neon Tetra (Paracheirodon innesi)
A freshwater fish from the Amazon basin in South America, This fish thrives in a darker environment. The fish has since adapted to most different tank living conditions since its first importation in 1936. Even so, It still requires a densely packed tank with a darker shade of substrate. [Source]
Recommended gravel type: Pebbles, Stones, clay
Recommended colour: Dark natural stones with vibrant natural colors mixed in
The bonus aspect of having a darker natural coloration in your Neon Tera’s tank is her highly reflective skin will really pop out. It’s very beautiful and one of the reasons it’s the most popular fish people have in their aquarium.