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The Many Aquarium Uses of Plastic Canvas (Mesh): Dividers and More

Marie is a lover of everything about and inside of aquariums. Among other friendly creatures, she has a turtle that she adores.


I love do-it-yourself (DIY) projects, especially when it comes to aquariums (because the hobby is expensive!). Out of all the materials I use for such projects, I frequently find myself using an arts and crafts material called plastic canvas, which is originally used for needlepoint. These sheets of plastic mesh are perfectly safe for aquarium use, they come in all sorts of colors, and they're extremely cheap. Here are some ideas for using plastic mesh; I have discovered many ways of using it to enhance the aquarium.

  1. Tank Divider
  2. Java Moss Background
  3. Filter Material
  4. Small Covers/Lids
  5. Algae Scrubber Filter Material
  6. Shading
  7. Adding Color
  8. Climbing Material/Ramp

1. Tank Divider

Probably the most common aquarium use for plastic mesh, tank dividers save people the trouble of purchasing another aquarium if one can utilize the space in the existing tank. Male bettas are a prime example of fish that can’t get along with its own species. By constructing a tank divider, you will ensure the two fish won’t be able to fight.

Of course, the same principle applies to other species of fish. In a 20 gallon long, you can keep a crayfish on one side and endler live bearers on the other, without fear of the crayfish eating the fish.

Warning: Make sure the animals will be happy in the space you provide them as the result of a tank divider. Also be sure the temperature and pH is within range of all species’ needs.

[original posting of this image has been deleted] http://www.kwas.ca/forum/showthread.php?5551-Moss-Wall-Pics

[original posting of this image has been deleted] http://www.kwas.ca/forum/showthread.php?5551-Moss-Wall-Pics

2. Java Moss Background

This is another popular use for plastic mesh. At one point someone came up with the creative idea to grow java moss on sheets of mesh. Java moss is a slow growing plant and it takes its time, but once it clings and spreads, you’ll have a pretty cool background for your tank. The picture below (not mine) is an amazing example of what you can accomplish with this concept. I'm sure the fish appreciate the extra plant life too.


3. Filter Material

With creativity and a dash of science, one can create an effective filter, even more so than those sold in stores (if you understand the importance of the nitrogen cycle, surface area, and water flow). Plastic mesh is a popular material for keeping filter media in place while allowing water flow.

I always use plastic mesh when creating an internal box filter for this purpose. I can also imagine it working for HOB filters.

4. Small Covers/Lids

Canvas mesh for needlepoint isn't sturdy, but it can be tied together with fishing line and fastened with poster borders to make for a secure lid. I never use lids unless I am keeping known escape artists, like frogs and crayfish, and the one I've built for my 15 gallon long is perfect.

You can also easily modify it. Just cut off an end of a poster border and you'll have just enough space to place an airline tube or a heater's cord. You could even cut out a space big enough for an HOB filter, although this can be tricky when dealing with escape artists. And of course if you make a mistake (like I clearly did), just tie a piece of canvas over the error.

This project can actually be a bit of work, but with patience you'll have a cheap, secure lid at your disposal.

Tips for Making Lids

For this one, I would use clear plastic mesh, unless you want very dim aquarium lighting. Even with clear mesh, lighting may still be dimmed to a degree (depending on how close the light is), so if this will cause an issue, you might incorporate plexiglass to areas that need more lighting. Some of my tanks just have plexiglass as a top (to prevent immense evaporation and retain heat).

5. Algae Scrubber Filter Material

For those with a high nitrate problem, an algae scrubber (despite its name) is a perfect filter, where you intentionally grow algae in a concentrated area using water flow and a long-running light source. The idea is the algae in the filter will outsource any other algae in the tank, ironically using algae to get rid of undesirable algae on glass, décor, etc., while the algae you've grown is hidden inside the scrubber.

Green algae also suck up nitrates, something a regular filter won't do; you'll rarely get green algae in an aquarium filter since beneficial bacteria prefers the dark.

Plants often suck up nitrates too, but it's typically a very low percent, especially for slow growing plants. And while plants are just there, absorbing the nitrates at their own pace, water is being drawn right to the algae of the algae scrubber, resulting in nitrates getting absorbed more quickly among the tank as a whole.

Plastic canvas is a great material for algae to grow on, although to be fair, just about any surface is susceptible to algae. However, the green stuff will most likely stick to the mesh because of the water flow accessibility that mesh has, and plastic mesh is easy to remove from the scrubber when the algae gets too thick (washing some of it off and placing it back in).

It is even better to use sandpaper or a sander to make the mesh that more "clingy" for the algae. The following video is the best video I've seen for making a simple algae scrubber for any aquarium.

6. Shading

I'm a strong believer in giving aquatic animals as many options as possible in the tank. By this, I mean creating a diverse environment, such as making one corner of the tank full of foliage (jungle-like), while providing an open space area for fish to swim freely without bumping into something. Lighting and shading in an aquarium is another way of giving your animals options, as some would like to be near the surface, close to the light, while others prefer darkness--a prime example would be the plecostomus.

So, if there isn't enough décor/plants to provide a lot of darkness in one area of the tank, then simply filter out the lighting with black canvas mesh. Placing it on top of the screen, underneath the light, is the simplest way to do it, but it depends greatly on how your lighting is set up. If the light is just hanging over the tank, you may have to get fishing line and find a away to tie it under.

Warning: Plastic canvas mesh, like most flexible plastic, can melt at a certain degree, so be weary of having it too close to the light. I would give at least an inch of space between the light and the mesh, but be your own judge.

7. Adding Color

So this is basically the same as shading, only instead of adding black to simply darken an area in the tank, you are taking advantage of the array of colors this mesh comes in. This is pure aesthetics; it doesn't matter to the animal what color its surroundings are; this is just to add beauty to the tank, especially if you have a color theme. This is still shading, only lighter. And it can benefit the animal if it doesn't like particularly bright lights (e.g., the betta fish).

8. Climbing Material/Ramp

This is good gripping material, and because it is aquarium safe, it only makes sense to use it when making ramps for semi-aquatic animals such as crustaceans, amphibians, and turtles. With lightweight animals like hermit or fiddler crabs, the mesh alone should be enough to support them. Heavy animals, like turtles, will obviously need something sturdier, but the mesh can still be glued/tied on the surface of the ramp to serve its purpose. To the right is a perfect example of mesh serving not only as climbing material, but for land space as well (and from preventing the crabs from escaping through the HOB filter!).

Warning: When cutting plastic mesh intended for animals to use, be sure to cut evenly so there are no sharp plastic parts sticking out; this can scratch amphibians, fish, and tear those with long fins.


Dee on July 24, 2020:

I made my Beta a hammock to rest in and he loves it i made sure there were no sharp edges and the wire to hang it is a jewelry one that wont rust

mariekbloch (author) on May 18, 2020:

I suppose, as long as there are no sharp edges that can snag their fins, or there is no way the fish can get tangled in it.

LNS on May 16, 2020:

Plastic canvas and acrylic yarn are both used in aquariums. In other hobbies they are used together to "build" decor. Could you use those techniques to diy decorations and such?

mariekbloch (author) on August 09, 2019:

I always wash off whatever I put in the tank. I doubt it was the mesh though. No, I've never had this issue.

Bcatelyn on July 30, 2019:

I recently divided two separate tanks with this canvas mesh and have since been experiencing cloudy water. Is this a common occurrence? If so what can I do?

Fish on April 25, 2019:

Walmart, Micheals and Joanna's carry it

mariekbloch (author) on July 28, 2014:

Well, Petco is not really a fish store; it's a pet store in general. They might have some, but if not look at your local fish/aquarium store. Good luck.

Ann1Az2 from Orange, Texas on July 26, 2014:

Wonderful! Next time I'm by a Petco, I'll stop in and see if they have any.

mariekbloch (author) on July 26, 2014:

Hello Ann, most fish stores have java moss. I don't believe fish will eat it.

Ann1Az2 from Orange, Texas on July 24, 2014:

I never knew there were so many uses for plastic canvas! I may try a few of these in my tanks. I love the Java moss. Do most fish stores carry it? Also, do you know if the fish like to eat it?