Will Magic Eraser Kill Fish? (A Detailed Explanation)

We are reader supported. When you purchase through links on our site, we may earn an affiliate commission. Also, as an Amazon affiliate, we earn from qualifying purchases.

When looking to clean the glass on the inside of your aquarium, you want to find the best and quickest way to get rid of things like mold and algae. This stuff can stick onto the glass with a vengeance, so much so that some people even use razor blades to remove it. While this is effective, it does scratch the glass.

So, there has to be something less abrasive. But what about Mr. Clean Magic Eraser? Will this kill fish? The answer isn’t simple, the jury is out. While most hobbyists and experts suggest not using it, there are some people who use it with great success. This means it will be up to each individual fish keeper to use at their discretion.

How Can Magic Eraser Kill Fish?

It’s imperative you stay on top of keeping grime, slime and other undesirable buildup off the walls of your aquarium. This could be mold, algae, bacteria or some other such thing that can cause your fish to get very sick and possibly end in an early grave. Therefore, when you have to clean it, you want to use all things that will be safe for your fish.

Some Aquarists Use It

Magic eraser is desirable for some aquarists because you can use it wet or dry and it removes all gunk and grime off the side of the tank. All except water and salt stains that is. It doesn’t work in a magical way against that. But it’s durable enough to quickly clean the tank and it’s gentle enough to not scratch the glass.

Many hobbyists in online forums and social media videos show how they use Magic Eraser in their aquariums with great success. Their fish seem to be happy and thriving without problem or incident.

Chemical Constituents in Magic Eraser

However, while it seems like a good idea in theory, it may not be ideal because of the chemicals it comprises. The main ingredients in Magic Eraser are formaldehyde, sodium bisulfite and melamine. Formaldehyde is what they use to embalm dead cadavers and sodium bisulfite is anti-bacterial.

Using something that goes into decaying bodies may likely spell disaster for your fish. While the sodium bisulfite may not hurt your fish directly, it can kill all the good bacteria that are in your tank. Plus, the melamine sponge has the potential to add nitrogen, which could also negatively impact the nitrogen cycle of your aquatic ecosystem.

Is There Anything Like Magic Eraser that Won’t Harm Fish?

While magic eraser itself has components that have the potential to be dangerous to fish, using a melamine sponge might be okay. Melamine comprises 67% nitrogen and is a wonderful fire retardant. When combined with things like formaldehyde, it hardens to create a resin to produce a thermosetting plastic. This makes for good insulation, laminates, soundproofing and cleaning products.

The Problem with Melamine

There’s a huge concern over melamine because there was a situation in the early 2000s where a powdered form was found in pet food and baby formula. Manufacturers promoted it as enriching their products with protein. The result ended up killing several hundred children and pets while injuring thousands more.

But, in sponge form, the active nitrogen becomes inert and you can find melamine sponges without formaldehyde or any other harsh chemicals. However, the concern still lies in wiping down a tank with it. This is because miniscule pieces of the melamine sponge can break off, some naked to the human eye.

If this happens and your fish swallow it, it could cause an obstruction in the fish’s digestive system. At the very least, it will cause your fish to get sick for a while until it passes. But, in many cases, it can kill the fish if it swallows one far too large.

What’s the Safest Way to Clean a Tank’s Glass?

Using chemical-free paper towels, a clean windshield scraper and/or a clean, dry and soap-free sponge is the best. This is the tried, true and trusted way to clean aquarium glass. It’s safest for fish and you can ensure it gets clean without scratching the glass.

You can use this method if you only want to reach your hand in and give a gentle scrub to the side of the tank or if you need to do a large water change. So, it’s very versatile this way. But, it does tend to be more time consuming than using something like Magic Eraser. This will be especially true if gunk is really stuck onto the glass.

Cleaning ; Upkeep

If you want to brush up the sides of the tank without removing water, always clean the tank glass when there’s only a little build up on the walls. If you cannot remove heavy amounts that flake off into the water, this can be damaging to fish.

When there’s a huge amount of buildup, you will have to remove the fish, siphon out the water, take out all the aquarium accoutrements and then clean the walls. This way you can remove everything safely without potentially harming your fish.

Using a Windshield Scraper

Make sure the windshield scraper is brand new that you reserve specifically for cleaning the tank. Avoid using ones that were for a vehicle, this will create havoc for your tank. Always clean off the scraper with your chemical-free paper towels after each use to keep it sparkling and free of bacteria.

Only use this when you have to get into the corners or because the glass is horrid. Don’t use the scraper when your tank is full. This is because it’s difficult to know all the materials it comprises, including coatings and finishes.

Final Thoughts

While it’s difficult to say if Magic Eraser will kill fish, it’s probably not the best thing. With ingredients like formaldehyde and sodium bisulfite, it’s too iffy. However, you can always try a melamine sponge. They do have risks, it will be infinitely safer than Magic Eraser.