Lightweight Safe Unbreakable Monsterfish Tank Covers

Stainless Steel Mesh Covers.

In this post, I will share about my Arowana tank covers which are safer, lightweight and do not block light and ventilation.

My criteria for tank covers are slightly more demanding than those for typical fish-only tanks as my tank is planted. Of course, the main reason for tank covers is to prevent our precious fish from jumping out. In addition, for planted tank purposes, I need to:

  • Minimise light blockage as the plants need light to grow well.
  • Minimise heat retention. Bright lights produce more heat, plus plants generally do better at lower temperatures (preferably 28 celsius and lower).
  • Maximise ventilation for evaporation. Evaporation helps water to lose some heat and not build up excessively under the lights.

The typical tank covers used by many fish keepers are glass, acrylic or egg-crate light diffusers. There are several reasons why I don’t like them.

Glass and Acrylic Covers

Both of these types of covers are usually transparent. However, due to water splashing, condensation and scale deposits, they block or diffuse the light too much for a planted tank.

Next, both get slippery when wet. Glass, in particular, and thick acrylic can be heavy. Most people cut holes in them for ventilation and grip, but I still find them unwieldy. The danger of dropping them is real and especially dangerous for glass covers as they could break.

If the holes are not well chamfered, they can cut both hands and fish. Glass edges may also chip in the long run.

These covers also trap heat as they do not allow much ventilation at all. Glass also heats up under the lights and the retained heat will at least slow down cooling after the lights go off.

Heat from the lights may also cause the acrylic to warp, so they will not cover the tank properly. Acrylic panels that are too thin will also sag under their own weight.

Egg-crate Light Diffusers

The main reason these are not good for me is they are designed primarily to diffuse light. That alone strikes them off my list. But there is another major factor that even fish-only keepers should consider. Although these are made of plastic, I realised many of them still have sharp edges on at least one side, if not both. They can cut the fish, or scrape off their slime coat or scales if they jump/scrape hard enough against them.

My Tank Covers: Stainless Steel Mesh

To meet all my criteria, I chose stainless steel mesh. They are significantly lighter than glass and thick acrylic. They are easy to hold and handle and do not get slippery when wet. They are nearly impossible to break. Light and ventilation blockage and heat retention are negligible. The smooth “bars” of the mesh also minimise injury to the fish if it jumps hard against it.

Rust was a concern, but after 8 years, there is very little rust on them.

While I chose these for planted tank reasons, I feel they are also good covers for fish-only tanks. Mainly because they are lightweight, difficult to break and safer for the fish.

Choosing the Right Mesh

The mesh has to be stiff enough so that it won’t sag and can’t be easily bent by a powerful jumping fish. Yet at the same time, it has to be soft enough to be easily flattened by hand and manipulated with hand tools such as wire cutters and pliers. I found the 2mm gauge (i.e. wire thickness) mesh perfect for this.

For the spacing, I chose 25mm as my Arowana was a 6-inch juvenile then. If you have larger fish you can consider wider spacing.

2mm Guage, 25mm Spacing Stainless Steel Mesh.

Where to Buy

I can only make recommendations for Singapore. Mine came from:

  • Lai ZinFeng & Sons Hardware Pte Ltd
    Blk 30, Kelantan Lane
    Singapore 200030


To make the covers, you’ll need a few simple tools:

  • A pair of wire cutters – I suggest showing the mesh to the hardware shop and asking them to recommend suitable wire cutters.
  • A pair of pliers for bending the wires.
Wire cutters and pliers
Wire cutters and pliers

Making the Covers

This part is straightforward. Normally, the mesh comes rolled up, so you will need to flatten them. Best to work on a large flat surface such as the floor or a large work table. The cut ends will scratch, so lay down some cardboard or similar to protect the surface and be careful while handling the mesh.

Once you have flattened the mesh, measure and cut to size and shape. In my case, I cut the mesh to overlap the tank bracing so that the mesh can sit on top of the bracing on all 4 sides. Then I cut out sections to fit around the plumbing.

Some work needs to be done to make the mesh safer for humans and fish. The cut ends of the “wires” are very sharp and are a safety hazard. I found that cutting the wires as short as possible (right up to the perpendicular wire) is a bad idea: although they are short and less “pokey”, they can still scratch quite badly. To prevent this, cut the wires longer and bend them back.

Cut the wires longer and bend them back over the perpendicular wire.

Securing the Mesh

There are many ways to secure the covers. For my specific purpose, I asked the tank maker to drill extra holes in the bracing for me to secure the covers. I then use reusable zip ties to secure the covers at the front. For the back, I wedge the covers under the return pipe.

Depending on your tank specifications, there are many other ways to secure the covers, including:

  • Weighing them down,
  • Attaching holders onto the tank hood, rim or bracing.
Secured with reusable zip ties.
Wedged under the return pipe.

Finished Product

And that’s it. Fairly easy to make, although bending those cut ends back is pretty tedious. The end product is a lightweight, safe, and neat cover with good ventilation, minimal heat retention and negligible light blockage for your tank. If you have any queries or comments, feel free to reach out to me. My Social Media links are at the top of every page.

Lightweight, safe, ventilated and neat.

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