What Paint Can I Use In an Aquarium That Is Not Toxic To Fish?

Painting your aquarium and the objects inside it can truly add to its beauty. However, you need to be very careful as some paints can be toxic to fish.

To determine what paint you can use for your aquarium, you need to figure out what you are painting.

Safe Aquarium Paint for Internal Use

It is extremely important to pay attention to the paint-covered objects that will be placed in your fish tanks, such as decoration pieces and pipes.

You don’t want the paint to peel or leach harmful chemicals within the tank, making it harmful for your fish.

Paint for Plastic, PVC, and Resin

Plastic is a common material used in aquariums for practical and decorative purposes. The best paint type for such objects is spray paint – you don’t need brushes or extra cleaning.

Spray paint is a great way to cover up the awful white PVC pipes that damage the aesthetic of your aquarium.

You can just spray some black paint so that they fade into the background.

When applying, the key is to spray an extremely thin layer in an evened-out coat to avoid dripping. You can spray on additional layers of paint later on when required.

The most widely used and recommended spray paint for an aquarium is the Krylon Fusion paint that is specifically designed for reef tanks.

Krylon K02424001 Fusion for Plastic Spray Paint, Satin Hunter Green

This paint clings on really well to PVC, plastic, and resin while giving these materials an uber-clean finishing.

The Krylon Fusion paint is extensively popular due to the massive variety of color options that it offers—so much so that no other paint brand can match up to it.

You won’t have to worry about your PVC pipes flaking. Even though this spray paint dries up in 15 minutes or even less, it can take a while for it to cure properly (at least a week) to ensure that it becomes chip-resistant.

Once you’re sure that the paint has cured completely, then you should rinse the object in dechlorinated water to get rid of any remaining residue and dust that has settled on the surface.

Don’t forget to prep the surface of the object before spray painting as this will help reduce the likeliness of chipping or flaking. You can prep the surface by cleaning and sanding it.

Paint for Glass

Krylon Fusion spray paint is great for painting plastics but what about other surfaces involved in aquariums such as glass?

There’s no denying that spray paints are a great option if you want to paint glass; however, Krylon Fusion may not be the best option.

If you want to paint glass, use Performix Plasti Dip. It might appear to be a normal spray paint but it dries up and transforms into a firm rubber.

Performix 11203 Plasti Dip Black Multi-Purpose Rubber Coating Aerosol - 11 oz.

This makes this product unique and suitable for aquariums as it won’t flake or crack even after being underwater for a long time.

You can also use this to spray on decorations that may otherwise seem unsafe for your fish tank.

You might be worried about those underwater creatures that love eating algae off surfaces. Don’t be concerned as they won’t be able to eat any rubber while eating the algae coating.

However, let the surface fully cure after the application of the final coat.

Paint for Other Materials and Surfaces

Spray paint should be pretty much your go-to option for most surfaces.

But spray paint might not be effective on some unusual surfaces within a fish tank such as bricks, concrete, or Styrofoam. In cases like this, you can turn towards Drylok.

Drylok water-proofer is popularly used in 3D aquarium backgrounds and is often considered as paint, even though it is not. It is a waterproofer that helps seal and protects surfaces from water.

Drylok 27512 Latex Water Proofer, 1 Quart, White

Drylok is white in color due to its purpose and properties. However, even though Drylok is available in multiple colors, it isn’t deemed as safe to be used in aquariums.

You can add Quickrete Liquid Concrete Paint to Drylok to add color to it and also ensure that it’s safe to be used within a fish tank.

The more Quikrete you mix with Drylok, the more vibrant the shade will turn out to be. By using different quantities of both, you can create different shades.

Now that you’re aware of what paints are safe to use within a tank, there are a few other options that can be applied externally on an aquarium.

Safe Aquarium Paint for External Use

Paint is safe to use on external surfaces as they’re not in direct contact with your fish tank residents. External surfaces include the glass of the tank, the trim, or your aquarium stand.

However, the most widely painted part of a fish tank is its rear glass panel. Generally, you don’t really have to consider which paint to use externally on your fish tank.

Many people, however, choose to use acrylic paint, Plasti Dip, or even matte paint for the background.

Additionally, it doesn’t make a difference whether you use glossy or semi-glossy paint as the glass will glare either way.

Just ensure that you use paint that gives your aquarium a smooth finishing and makes it pop.

The most commonly used colors for aquarium backgrounds are blue and black – blue being more commonly adopted for reef tanks.

You can also paint it black to camouflage the heater, filter plumbing, pipes, etc.

You might also be wondering why people paint the external surface of their tanks. Well, painting the rear and sides of your fish tank allows you to spot your fish and plants more easily.

It helps block any distractions that may be on the other side of the aquarium.

Related: How to Fix a Leaking Aquarium without Draining?

How to Recognize a Fish Tank Safe Paint?

As mentioned before, you cannot use any type of paint within your fish tank since not all paint is aquarium safe.

It can be difficult to look for a paint product that serves your functional aquarium well.

When looking for paint that is safe for fish tanks, find something that is labeled with ‘for use in potable containers’ or ‘food safe.’

These two indicators imply that the paint is non-toxic for your fish, making it safe for your aquarium.

The best way to know if paint works well or not is to wait out a full cure. Curing is the process by which the paint reaches its maximum hardness.

Spray paints used on plastic will become chemically inactive once the curing period ends.

Paint that has fully evaporated solvents and is cured completely is deemed safe for aquarium usage.

It’s safe to say that any paint product that hasn’t been fully cured is toxic for a fish tank.

How Dangerous Is It To Use The Wrong Paint In Your Aquarium?

While your aquarium gives off very calm and soothing vibes, it is actually a very harsh environment for paint. Paint doesn’t tend to respond very well when it’s exposed to water.

Many paints absorb water and begin to bubble or peel off. These flakes can be perceived by your fish as fish flakes, so your pet might munch on them.

We’re pretty sure you know why this shouldn’t be a part of your fish’s diet. It is extremely harmful to your fish pets and can also result in their death.

Sometimes, the paint appears to be holding up just fine, but it is actually releasing harmful chemicals in your aquarium.

These chemicals might not be visible to the naked eye but are indeed very deadly.


As aquarium enthusiasts and owners, it is really important to make sure that you use products that don’t harm your underwater pets.

So, when it comes to selecting paint for your aquarium, you have to be extra cautious to ensure that it’s non-toxic for your fish pets.

To pick the right paint for your aquarium, you need to decide how well the paint performs underwater and how durable it is.

You also need to determine whether you are painting the inside of the tank or the outside and the surfaces you will be covering. All these factors can help you choose the paint for your aquarium.

However, regardless of the paint type you choose, ensure that you let it cure properly before placing the object within your fish tank.

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