Can you put metal objects in a fish tank? {Safe To Do?}

We found out that a lot of people want to know some basic things about caring for their fishes and their fish tanks. Like can you put metals in a fish tank?

Is it safe to do?  Will the metal harm your fish?

Can you put metal objects in a fish tank?

The simple answer is no! You should not allow metals in your tank. For a short time, maybe! But should you put metals in your fish tank for a long time? Absolutely not!

In any case, you might also want to know other things. Like what can put in your fish tank that won’t bring up any complications?

The answers to all your questions are right here.

Should you allow metals in your fish tank?

We advise that you avoid it as much as you can.

In truth, metals can bring some chemical changes to the content of your fish tank. The changes might be beneficial, but it is not often wise to take these chances.

metal objects in a fish tank

See, metals with time become corrosive. They begin to form oxides on the surface of your fish tank. These oxides might, in turn, become poisons that will spell the end of your innocent little fish- your innocent, sweet fish that just wants to swim around the fish tank and appear cute all day.

What you already know

If you are just setting up your tank, there are some things you might already know. Some of these things include the size of the tank that you want to get or the kind of fishes you will keep probably should know some things already about your fishes.

A cool supplier might inform you about some specific things you should and should not do- most notably the don’ts. However, not everyone will take the time to educate you.

So just what do you need to know about your fish tank?

Why you might want to use metal in your fish tank

One of the top reasons why some hobbyists introduce metals into their fish tanks might be to get rid of black worms. Black worms can be really disgusting when they manage to find their way into your tank.

Some people would recommend that you use copper specifically to eliminate them. However, this action has some level of repercussion on your lovely fish.

What happens when you put some metals in your fish tank?

Metals have the potential to cause a lot of problems for your fishes.

Some of these problems include:

  • Delayed Hatching: The metals contain chemicals which can delay your fishes’ eggs from hatching at the right time. Eventually, this affects the overall rate of reproduction of your fishes. But this is only a subtle way that metals can affect your fishes.
  • Metal might deform your fish: A more aggressive effect would be the deforming of your fish. Crazy right?!
    Metals can be really hazardous to marine life- especially to sensitive fishes.

We are sure you don’t want your sweet guppies or dwarf gouramis looking abnormal. So keep that metal away.

  • Altered growth rates: Metals in your fish tank can slow down the growth rate of your fish. It will lead to a longer time before your fishes complete their cycle.

Ultimately, the presence of metal in your fish tanks can make it a lot more difficult for your fishes to survive. Why should you do something that will make those cute creatures suffer?

We advise that you stay away from using metal in your tanks as much as you can.

If it is unavoidable, though, a good choice would be to coat them with an epoxy that’s aqua-friendly to prevent the completion of the oxidation process that might poison them.

Things that can safely go in your fish tank

If metals should not go into your fish tank, what then can go in there without causing any troubles or complications? That’s something we think you’d want to know.

So yes, here are some of the things that can go into your fish tank:

  1. Glass: Glass, unlike metal, is not corrosive. It doesn’t begin an oxidation process after a period of being in your tank for too long. It would make a pretty great addition to your fish tank.
  2. Plants: Plants give that more natural feel to your fish tank. Seriously, what will a fish tank look like without plants? You don’t even want to think about that.
  3. Wood: Wood, like plants, would also make a great addition to your fish tank. They occur in nature and are found in the oceans anyway. So, there’s no reason at all not to add them to the mix.
  4. Rocks: A fish tank with plants and wood? Cool! A fish tank with rocks, plants, and wood? Now, that’s even more interesting. Rocks reinforce the natural feel to your fish tank and make your fish feel more at home.
  5. Seashells: Colorful seashells look great in your fish tank. When someone stares at your fish tank, you want to give that impression that they’ve made a trip to the ocean. They have seen all these things- without leaving the comfort of your home.

Also, who knows, you might consider keeping hermit crabs soon.

Some of the other things you can add to your tank include plastic decorations, reefs, and other household materials. Basically, anything you feel like adding into your fish tank. There will be no problem at all- as long as you browse them first and ascertain if they are harmless to your fishes or not.

What you put in your fish tank is really important. What you choose to keep out of your fish tank is also equally important. At the end of the day, it is the combination of these things that will determine how healthy your fish are.

So pay attention to these things. Get all the good stuff in. Keep all the bad stuff out of your fish tank- especially metals.

As you have put together a comfortable home for yourself, create a conducive and relaxed atmosphere for your fish as well. After all, it is essential that it really likes its new home. Okay, maybe it might not be that important to other people, but not to us- hobbyists.


Hello, I'm Jason. I'm the guy behind I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.