When to Add Fish to a New Planted Tank + Maintenance Tips

Not only do planted tanks look good, plants can be very beneficial to your fish! However, you need to know when to add fish to a new planted tank, as one mistake might cost you your entire collection. 

You’re probably familiar with something called ‘a cycling cycle’. A planted tank still needs to go through a cycling cycle. This can impact when you are able to add inhabitants to your aquarium.

How does cycling impact the plants? When to add fish to a new planted tank? If you are unfamiliar with this and many other information about plants and fish, don’t worry – you’re in the right spot.

Here is everything you need to know about new tanks, plants, and fish!

When to Add Fish to a New Planted Tank

Many novice aquarists think that you can add fish to the tank right away, especially if you have plants in it. In the end, plants provide oxygen to the tank. What more do fish need?

The truth is, you should wait for about 6 weeks before you can add fish to a planted tank. This is just the right time for healthy bacteria to grow inside your aquarium. 

In general, these good bacteria eat toxic ammonia and turn into a somewhat healthier nitrite. However, plants also eat ammonia. This might speed up the cycling cycle for a bit – as long as there is enough ammonia to feed both the bacteria and the fish.

High levels of ammonia can also be harmful to fish. This is why it’s important to regularly change the water, even when you have plants.

Cycling a Planted Tank

Cycling a planted tank isn’t that different than cycling a regular tank. 

You put water into the tank (some people use tap water but I prefer using RO/DI water), add a filter, and put some ammonia as a food for bacteria. 

Another option is to put some fish food into the tank and let it rot. Over time, the food will rot, increasing ammonia levels. 

When you have plants, you’d want your ammonia levels to be just a tiny bit higher than regular. In general, 2 ppm concentration of ammonia is the right amount for the first few months. 

If you’re uncertain how much ammonia there is in your tank, you can simply buy a water testing kit. It will show you all the parameters right away. 

While you want your ammonia levels to go lower, you need to think twice when you notice the levels going down. 

There are two reasons why this might have happened: The bacteria ate it or the plants consumed it. 

When you don’t have plants in your tank, everything is pretty much straightforward. Lower ammonia levels mean the bacteria levels are growing, which is precisely what you want to happen.

However, when you have plants, it’s more likely than not that they are the main culprit. This is why you want to make sure your ammonia levels are fairly stable for at least 6 weeks. 

Otherwise, you are risking adding fish to an unprepared aquarium, which might halt their growth, ruin their health, or even be deadly.

Can You Add Fish Straight Away?

In theory, you can always add fish straight away. In fact, this is how aquarists used to cycle their tanks in the past. They would add some hardy fish into their aquariums and use them as a source of ammonia.

However, as this method risked fish lives, it is mostly abandoned in the modern times. I’ll explain why.

When you’ve just added water to your tank, there are no beneficial, ammonia-eating bacteria in it. Fish need to poop, and this poop will lead to increased ammonia levels. 

Without bacteria that will eat ammonia, the ammonia levels might rise uncontrollably. This can lead to the death of your fish.

Still, there is one way to immediately add fish safely: instant cycle.

Instant cycle means that you use filter media from an established tank into your new tank. This will immediately add all the necessary bacteria. 

While the bacteria amount might not be as high as if you’ve waited for a full cycle, it will be high enough to consume all the ammonia – as long as you don’t have too much fish inside. 

Can I Add Plants to a Cycling Tank?

It doesn’t really matter whether you’ll add plants to a cycling tank, to a pre-cycled tank, or after you’ve cycled it. Ammonia is not toxic to live plants – quite the opposite, it’s their fertilizer. 

Whenever you add plants, you’ll make sure you’ve added another method of breaking down ammonia from the water. Your fish will always benefit from that.

However, most people would recommend you add plants before you’ve cycled the tank. This is because they will make your aquarium safer for the fish, especially in the earlier stages.

Other than that, there is nothing stopping you from adding plants to a cycling tank. The only thing that will change is that you’ll need to start maintaining stable ammonia levels instead of allowing them to drop immediately.

New Planted Tank Maintenance

Just like you’d want your aquarium glass to be crystal clear, you should also take care of the water inside the tank from day one. This means there needs to be some maintenance when you’ve made a new planted tank.

In fact, you’ll need some specific care tips when dealing with a planted tank! 

Some of the things you need to do daily is to add liquid carbon and fertilizers. This will provide food to your plants. If you already have fish inside the aquarium, you don’t need to worry about fertilizers. Fish poop and urine will do just fine. 

Make sure all the dead leaves are removed as quickly as possible. Otherwise, you’re risking algae. A good idea is to add some shrimp, such as crystal red shrimp or ninja shrimp, that will eat both algae and dead plants.

Weekly maintenance isn’t that different from maintaining the rest of your tank inhabitants. Change a portion of the water, make sure all your equipment is working properly, and check the water parameters. If needed, trim your plants.

Once a month, you need to check your filter. A filter might get more dirty in a planted tank than it would in a tank without plants due to all the biofilm. Just remember not to go overboard, or you’ll kill beneficial bacteria.

Do Fish Like Heavily Planted Tanks?

Some aquarists love adding plants to their tanks. Others are afraid that their fish might eat the plants or that plants might harm the inhabitants. So, what is the truth?

You don’t really need live plants in your aquarium. Your fish don’t make a huge difference between live and artificial plants. They simply want a natural-looking hiding spot, and plants provide this to them. 

Sure, plants produce oxygen, but so does your filter. In fact, plants can never replace a filter, even if your tank is heavily planted. 

Also, they reduce algae growth, but they also consume ammonia necessary for the growth of beneficial bacteria.

Not just that, but a tank that is heavily planted might not be suitable for larger fish as they’ll have less space to roam. 

In the end, it comes down to you and your preferences whether you’ll keep plants in your tank or not.

Final Word

Plants look beautiful and they are among the favorite decorations of many aquarists. However, just because plants can be good for your fish doesn’t mean you can add them right away. You need to know when to add fish to a new planted tank, or you’re risking trouble.

Planted tanks still require cycling. You need to wait for healthy bacteria to grow, otherwise the ammonia levels might get too high.

If you’ve already cycled your tank, you can add plants right away. There is no reason to wait! Plants are always beneficial and they might help your fish out. 

Of course, modesty is the key, and you shouldn’t go overboard with plants. Add a few at a time and see how your fish will react!  You’ll have a beautifully planted aquarium in no time!