How to Paint a Realistic Watercolor Fish Tank Background

A store-bought fish tank background is usually a solid blue or black, or has a shiny aquarium scene complete with plants and rock pictures. While this solution to aquarium decor works, some desire a less picturesque backdrop. Creating a soft-focus yet still realistic watercolor fish tank background is a great solution.

Watercolor Fish Tank Background - Materials Needed

The most important material for the fish tank background is a piece of watercolor paper, or other suitable material, that covers the entire back side of your aquarium. You will also need watercolor paint in dark blues, greens, and black, water, and paintbrushes. Paper towels for clean up are also a great idea. To affix the fish tank background to your tank, double sided clear tape is ideal, although you can use regular tape as well.

Watercolor Fish Tank Background - Painting Tips

In order to make a realistic watercolor fish tank background, you should start with a dark background color. Since you want the lights in the tank to focus on your colorful fish, the backdrop should not be bright and garish.

Begin by painting the entire piece of paper with a dark blue color. Use a horizontal stroke motion instead of a verticle one. This looks more like natural variations in water layers. You can use green or black to vary the tint of the blue layers slightly. The bottom part of the fish tank background should be darker than the top.

Watercolor Fish Tank Background - Decorating Tips

After you have the basic dark blue color for the backdrop, you may want to decorate the fish tank background with some rock or plant pictures. Match the colors and styles of rock paintings to the ones you are using in your aquarium. The idea is to make shadowy images of rocks and plants, unless you are a great artist and can draw ones that are totally realistic.

Use black, dark grey, and browns to paint rock shapes on the fish tank background. Then, mix darker green colors and paint plants. Simple ribbon-shaped leaf patterns are a good choice for less-than-perfect painters. Skinny stalks with oval leaves can imitate Amazon sword plants. Small round leaved paintings can look realistic too.