One of the big advantages of growing plants in a fish aquarium is that the fish and plants each provide each other with health necessities.

The fish waste contains nutrients plants can use to grow.

But you can’t always count on the species in your aquarium to provide everything they need to each other. And just as you’ll likely need to provide food to the fish in the tank, you’ll also need to supplement the nutrition of the plants in your tank.

It’s pretty easy to tell when plants aren’t getting enough of the big 3 (phosphorous, potassium, and nitrogen), but trace element deficiencies aren’t always so easy to pinpoint.

By starting the right nutrient regimen, though, you’ll likely see an extra boost in plant growth and vibrancy.

Here’s a little more information about why you should add trace elements to your live plant aquarium...

What are the fish providing my plants?

Before you start adding nutrients to your tank, it’s good to know what’s already going on in there. The primary element that fish waste provides for plants is nitrogen. So you’re probably good on that one if you have a reasonable ratio of fish to plant life.

In fact, if you’re running an aquaponics system or live plant fish tank already, this self-dispensing nitrogen was probably a key factor in the decision. It’s a beautiful system. And it’s one less thing for you to worry about, since nitrogen is one of the most important nutrients for your plant.

So let’s talk about what your plants can’t get naturally from this setup.

What don’t the fish provide?

The fish in your tank probably are providing small amounts of other nutrients in addition to nitrogen, but not enough to maximize the potential of your plants. And what’s the point of a fish tank with live plants if not to have beautiful plants growing in there?

In addition to the nitrogen and other major nutrient elements, your plants will benefit from trace elements like iron, manganese, zinc, and boron, as well as others. Look for a trace element source that does not add extra nitrogen to the tank.

Fish waste also provides some potassium and phosphorous (the other macroelements in the big 3), but it’s not going to be enough to support your plants. So you’ll want to keep those in your nutrient regimen as well.

The right combination of nutrients strengthen plant connective tissues and aid in photosynthesis, so that your plants can utilize energy to grow.

What if there are no fish?

I have not forgotten that aquascaping is its own rewarding form of gardening. And in this case, no fish may be present at all.

If you just want to grow beautiful plants underwater, all of this advice still applies to you and your aquarium garden. You’ll just need to make sure that you’re also adding a nitrogen-rich fertilizer to keep those plants healthy.

Confused about which nutrients your aquarium needs? Reach out to us at Indoor Cultivator. We’re happy to answer your indoor gardening questions.