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How to find the Ideal Plant Substrate for Aquariums

Plant Substrate for Aquariums

If you’re just getting started with aquarium plants in a freshwater tank, then you’re likely to come across plant substrate for aquariums at one point or another. But what exactly is it?

The fact is, plants need soil and nutrients to be able to live, and grow, and survive! Planted aquarium substrates therefore emulate or mimic the soil or ground that submerged plants can get the nutrients they need. If you are letting your aquatic plants take root, then it’s important to have some form of substrates mix at the bottom of your tank.

When it comes to floating plants, this isn’t important – but if you really want to grow your own underwater garden, there needs to be more than fish, water, sand, and gravel in the best aquariums.

In this guide, we will take a look at what you need to know about plants and substrates, and what you should be looking for in the best nutrients and aquatic soil setup for your plants.

The Best Plant Substrate and Laterite Brands for Your Aquarium

Before we dive into ‘aqua soil’ and take a look at a few common questions asked about aquarium substrate, here are a few of the top picks for aquarium soil and laterite that you’re able to find online. The substrates in the group below are super nutrient-rich, and you’ll normally be able to spot them on Amazon, if not through the manufacturer or brand website to purchase directly.

CaribSea Eco-Complete Planted Aquarium

Caribsea Eco-Complete Live Planted Substrate (20lbs/9kg)

This top pick for aquarium substrate comes in either black or red varieties and contains tons of essential nutrients your plants will love. This is definitely one of the best eco-friendly substrate options out there, hence the name!

It’s free from anything nasty that’s likely to create algae, and it has a neutral balance. There are vital elements in this mix such as calcium and iron, and it’s ready to go without rinsing.

Seachem Flourite

Seachem Flourite 7kg

This iron-rich substrate for your aquarium also has a neutral balance and is pretty tough! It is easy to lay down on its own, or you can even mix it up with other types and brands of aquatic gravel if you really want to create a whole new look.

This is an ideal aquatic substrate if you’re looking to bring more iron into the water but are worried about upsetting the pH balance.

API First Layer Pure Laterite

This product is not a substrate but a laterite, which is a type of natural clay used to layer the bottom of fish tanks and aquariums. This particular brand is popular for the fact that it’s both natural and granular, making it safe and simple to set up for all kinds of water plants.

What’s more, this particular mix is formulated to be particularly safe for tropical fish, meaning it’ll be harmless to use alongside your critters and really beneficial for your plants.


Fluval Plant and Shrimp Stratum

Picture 4 of 4

Referred to as an ‘alternative’ substrate, this product is porous and easy for plants to adapt to. It’s even great for giving a hiding place to growing shrimp! This substrate is designed to work well with neutral to slight acidity in the pH, meaning it’s a safe pick for most freshwater aquariums.

This is a natural resource that encourages plants to absorb and obtain nutrients.

Activ-Flora Lake Gems for Aquarium

Available widely on Amazon as well as across pet stores online, these gems are great for giving your tank an authentic ‘sea bed look’, while still unlocking plenty of trace elements and nutrients to help keep your aquatic plants happy and healthy.

This product is designed to keep your water neutral, which means there is zero chance of it changing the pH. It’s natural and comes packed with iron, too.


Do you need special substrate for aquarium plants?

Ideally, you should be looking for a substrate that doesn’t ‘upset the balance’. That is, is should be neutral, as well as offering lots of nutrients and growth potential, as well as made from a substance that keeps your tank pH at the level you expect.

You should also look for a substrate that keeps the water hardness level the same, too. You should ideally look for a substrate mix which doesn’t come packed with acidity-boosting coral and gravel, and alkaline mix which is likely to stimulate algae.

There needs to be that balance in the middle – a neutral pH or at least a mix that is thoroughly tested so it doesn’t change the properties of your tank water. Otherwise, you are at risk of doing serious harm to your fish, plants, shrimp and any other creatures or organisms within.

How do I choose a substrate for my aquarium?

You need to consider the different species of plant and fish in your tank before you choose a substrate mix outright. This is because some substrates contain gravel, which can be harmful to some fish that are likely to eat it!

You’ll need to look for a mix, as mentioned above, which is developed to offer no effect on either the hardness or the pH balance in your tank. The whole point of a great substrate is that it acts as aquarium soil – so that it is purely nutrient boosting for your aquarium plants, and unlikely to ever cause problems for other creatures.

There are plenty of different mixes out there. The fact is you are likely going to need to look for a mix that suits your needs over time. You might find picking between Ada Aquasoil, various protein skimmers and otherwise a bit tricky.

However, consider your specific plants, and your specific fish, and do ask for the opinion of your local aquarium store expert, too. The fact is different substrates will serve different purposes – and the last thing you’re naturally going to want to do is find a mix that’s going to cause more harm than good.

Can I plant aquarium plants in gravel?

You can, but gravel is not always recommended for planted tanks.

Gravel is commonly used in many cases by all kinds of tank owners – beginners and otherwise – but this doesn’t always make it a good thing.

As mentioned, there are some fish who may try to eat bits of gravel or stone without realizing what it is they are chowing down on. This could lead to serious stress for some fish, or even choking.

Gravel can be safe depending on the size, and many people find it useful to hold plant roots in place.

There are plenty of discussions over whether or not gravel is actually beneficial for fish – but on the whole, it is likely a better idea to look for a pure, natural substrate, is this is going to give your plants what they desperately need, while not putting your fish at risk.

Can I mix gravel and plant substrate?

Yes – you can in some cases. However, planted tank substrate is likely to work better on its own, purely for the fact that gravel alone, or in a mix, can prove harmful to some fish.

A planted aquarium substrate is designed to act as the sole bottom surface of a tank for a variety of plants. Therefore, if you are keen to set up a complete planted aquarium, it makes sense to look for planted tank substrates that give you the ‘whole mix’.

Some experts and tank owners will advise that mixing is fine, however, so make sure to take a look at a wide range of sources and opinions before you make up your own.

There is a lot of confusion out there, so if you are buying things like inert substrates off Amazon, make sure to read buyer reviews. These will let you know what you can expect straight from people like you who are likely to use these mixes!

Can you put sand on top of gravel in a fish tank?

It’s not advisable to put sand on top of gravel in a fish tank as this can lead to the gravel rising up. The sand will, eventually, crush to the bottom.

Therefore, it may be worth using some form of landscaping or substrate system to balance them out. Do also keep in mind that there may be some filters which do not react properly to gravel and sand mixes, so take caution.

How often should I change aquarium substrate?

The type of substrate you use will alter when you should ideally change it. For example, if you have a high pH, you may have to change substrate out every few weeks to make sure that it keeps the same balance for your water and your animals.

However, a neutral balance won’t likely demand any need for substrate changes, all you’d normally have to do is just keep everything clean for the sake of your fish. You might want to change the substrate out occasionally, however, if there’s a need to give your plants more in the way of nutrients.


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Erik Miller

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Hello, there. Welcome to my blog. I am Erik and I’m the main editor of Sealife Planet website.

My passion and hobby has always been scuba diving. My mission is to grow this website and help others with useful information about the sea world. Enjoy! is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to

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