If you’ve been exploring the world of semi-hydroponic planting, you’ve probably heard people talking about both Leca and perlite. They’re among the most popular growing options in the soil-less growing world. But while these two growing media have a lot in common, they’re far from identical and one may be better suited than the other to your semi-hydro growing.

So let’s look at LECA vs. perlite to see their strengths and weaknesses as plant growth media and when you should use each.

What is LECA?

LECA is an acronym standing for Lightweight Expanded Clay Aggregate. It’s a growing medium, or substrate, made by heating clay pellets to high temperatures. When the clay is heated, it expands quickly (“popping” like popcorn, is how it’s often described), forming thousands of tiny bubbles. The bubbles give it an incredibly porous surface that make it great at soaking up water. And this makes LECA a popular choice for hydroponic and semi-hydroponic growing systems, providing superior drainage and aeration while retaining life-giving moisture.

The BEST things about LECA:

• Moisture-Retention: Highly-porous surface absorbs and stores water
• Breathability: Space between LECA pellets allows roots direct access to air
• Reusable: LECA balls can be washed and reused several times
• Inorganic: LECA helps reduce the bacterial and fungal growth that can cause root rot

Click here to learn more about LECA and how to use it

What is Perlite?

Perlite is a volcanic glass that has been heated to high temperatures until, like LECA, it “pops” to form lightweight and porous granules. It’s also a popular growing medium for plants because it’s lightweight, porous, and provides excellent drainage.

Perlite is best known as those white, styrofoam-looking specks you’ll find in many indoor potting soil mixes. It’s added to potting mixes to give a boost to soil aeration. But perlite can also be used as a standalone semi-hydroponic growth medium, working best for plants with fine root systems, like succulents.

The BEST things about Perlite:

• Aeration: Perlite’s porous surface helps retain valuable air in soil mixes
• Drainage: Perlite retains less water than LECA, draining faster for a less humid root zone
• Inexpensive: Perlite costs less versus LECA to get started, but has a shorter usable lifespan
• Inorganic: Like LECA, Perlite helps prevent bacterial and fungal growth

LECA vs. Perlite for Semi Hydroponics

LECA and perlite have their strengths and weaknesses as soilless plant substrates.

For example, LECA can be expensive and difficult to find in some areas, while perlite can be messy and dusty. Additionally, some plants may prefer one growing medium over the other, so it’s important to consider your specific needs when choosing between LECA and perlite for a semi-hydro soilless growing setup.

Take a look at how they stack up on a few important factors:

Water Retention

Perlite doesn’t retain water very well and, on the contrary, is known for its superior drainage capabilities. This makes it perfect for adding aeration capacity to heavy soils, but less ideal for creating a moist growing environment on its own.

As a semi hydroponic growth medium, it’s better suited for growing cuttings (with small root systems) and for plants that don’t want too much water, like succulents, cacti and spider plants.

LECA also drains very well (we’ll talk about it as a soil additive later), but it does a better job of holding in moisture than perlite. LECA can retain up to 30% of its weight in water and it’s porous structure creates a powerful capillary effect. This menas it can pass water up from a bottom reservoir very effectively, making it a very popular medium for semi hydro planting for a whole range of your favorite plants, from succulents to ferns.

Nutrient Retention

When talking about nutrient retention, you should know about the term cation exchange capacity (CEC). According to Purdue University, CEC refers to the ability of soils to store agroup of nutrient calcium (Ca++), magnesium (Mg++), potassium (K+), ammonium (NH4+), hydrogen (H+) and sodium (Na+). For this reason, it’s used to measure soil fertility.

When comparing the CEC of LECA vs. perlite, it’s important to note that neither scores particularly high. But LECA does come out on top, which means that it can more effectively store nutrients your plants need to thrive. Both of these substrates are inorganic, so they don’t provide any nutrient value on their own. But your semi hydro plants in perlite might need slightly more frequent fertilization than those in LECA.

Cost/Expense

You’ll generally pay a bit more for LECA upfront than you will perlite, but the cost difference isn’t so big. Especially when you consider that LECA will generally last you longer and can be reused multiple times.

This 2L bag of LECA will run you just over $12 ($6/L) on Amazon, but you’d need 2 of them to fill an 8″ pot for a medium-sized houseplant.

And this 40L bag will set you back almost $50 but is a much better deal at just $1.25/L.

Meanwhile, this 8 quart (~7.5L) bag of Organic Perlite by Perfect Plants runs about $2.20/L. And you can score a 29 quart (~27L) bag for just about $1 per liter.

Durability

LECA is the clear winner vs. perlite when it comes to durability. As we discussed earlier, perlite is light and fragile. It’ll turn to dust right between your fingers, and once it starts to break down then it loses it’s best properties (aeration).

LECA, on the other hand, is still remarkably light but significantly more durable. You can sterilize your LECA balls after use and put them to use on another plant. Some folks claim that the lifespan of these clay balls is almost indefinite. While I’ll call that an exaggeration, you should be able to get at least several years’ use out of them.

Ease of use

Both LECA and perlite are easy to use and help you avoid the mess of planting in soil. Plus, they’re a natural protection (although not a panacea) against many pests. When it comes to using LECA or Perlite as a standalone growth medium, LECA is my preferred choice for most plants. Ho

LECA vs. Perlite in Potting Soil

Both LECA and perlite can added to potting mixes to add a range of beneficial properties. We’ve already talked about the water-storing and aeration capabilities of both media, which make them a welcome addition to any soil. They can keep the soil from compacting to ensure readily available oxygen to your plant’s roots. And they store water longer to keep your soil moist without being overly wet.

The same characteristics we talked about in the semi hydro section apply. LECA balls are a bit better at storing nutrients, but that’s not as critical in a soil-based system (where the soil will have an even higher CEC). And perlite is both more affordable and more readily-available, which is why you’ll find it as an additive in many ready-made soil mixes.

Overall, perlite’s smaller size and lighter weight make it the more popular choice, but LECA is an often-overlooked option for adding to soil mixes .

Environmental Impact of LECA vs. Perlite

When it comes to choosing between LECA and perlite, both materials have advantages and disadvantages in terms of sustainability.

LECA is made from clay that is heated to high temperatures, which requires a lot of energy. However, it is a natural material that is completely recyclable. It is also long-lasting and can be reused in a variety of ways, such as for drainage in potted plants or as insulation in buildings. So you do get a serious return on the energy investment required to make it.

Perlite, on the other hand, is made from volcanic glass that is heated to high temperatures. While this process also requires a lot of energy, perlite is a naturally occurring material that is abundant and easily accessible. It is also completely recyclable and can be used for a variety of purposes, such as in horticulture or as a lightweight aggregate in concrete.

Personally, I don’t see a big difference here. I’d make my choice based on my needs and priorities, and just try to reuse my media as much as possible. Neither one has going to fill up landfills or add to the plastic waste in the oceans, they’re naturally-occurring materials.

LECA vs. Perlite: Which Plants To Grow In Each?

When deciding between LECA and perlite, it often comes down to what you want to plant. Here are some general guidelines to help you determine which medium is best:

LECA Is Great For…

Plants that require high humidity: LECA is a great choice for plants that require high humidity levels, such as tropical plants and ferns. The clay pellets can absorb and retain moisture, creating a humid microclimate around the roots.

Plants that require aeration: LECA provides excellent aeration for plant roots, making it a good choice for plants that require well-draining soil and plenty of oxygen. This includes plants like succulents, cacti, and orchids.

Plants that require stability: LECA is heavier than perlite, which makes it a good choice for larger plants that require stability. The weight of the clay pellets can help anchor the plant in the pot and prevent it from tipping over.

Some LECA plant recommendations:

• Araceae family plants (like Philodendron, Monstera, & Alocasia)
• Ferns
• Orchids

NOTE: For more inspiration, discover our 13 Best Houseplants for Growing with LECA

Perlite Is Great For…

Plants that require fast-draining soil: Perlite is a lightweight, porous medium that provides excellent drainage. It’s a good choice for plants that require a fast-draining soil mix, such as succulents, cacti, and other desert plants.

Plants that require aeration: Like LECA, perlite provides good aeration for plant roots. It’s a good choice for plants that require well-draining soil and plenty of oxygen.

Plants that require a lightweight medium: Perlite is much lighter than LECA, which makes it a good choice for hanging baskets and other situations where weight is a deciding factor.

Some perlite plant recommendations:

• Snake plants
• Succulents
• Cacti
• Cuttings & seedlings

And The Winner Is…

Everybody hates a cop-out…but the truth is that there’s no true winner here. Both LECA and perlite have their advantages and disadvantages for growing your plants. Your choice between the two will depend on your specific needs and preferences.

Personally, I’ll choose LECA 9 times out of 10 when it comes to growing houseplants in a semi hydroponic setup. It just seem to do a better job of wicking water and nutrients up to the soil zone to keep plants happy and healthy while giving roots access to oxygen too. If you’re ready to get started with LECA, check out our guide on how to prepare LECA for planting.

That said, there are still some cases where I’d prefer perlite, specifically for succulents or other plants that might struggle with too much humidity. But LECA can usually do the job just fine for those plants too.

Perlite is a bit more flexible and easier to work with in soil mixes. It’s more cost-effective, too. but either one of these media will help you get better results when growing in soil.

Now that you understand the key differences between LECA vs. perlite, you can strategically choose the perfect growth substrate based on your plant or project. Happy planting!

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