Eliminating Heavy Metals and Microplastics

We do not "eliminate" heavy metals and microplastics from our algae supplements. We prevent them from getting in. If you have ever scrubbed a stain out of a white shirt and thought "I should have worn an apron," you understand the principle. It is easier to keep something clean than to clean it up afterwards. That distinction describes a fundamentally different quality philosophy.

How Heavy Metals Enter Algae Supplements in the First Place

Algae are biological sponges. They absorb dissolved metals from their growing water, particulates from the air above them, and trace contaminants from the nutrient inputs used to feed them. In an open-pond system, all three exposure pathways are active simultaneously.

In a sealed photobioreactor, the first two pathways are eliminated entirely. The third is controlled by sourcing food-grade or pharmaceutical-grade nutrient inputs. The contamination route is always the same: the growing environment introduces what the organism then concentrates.

Removing metals after harvest is technically possible through acid washing or chelation. But those processes damage the nutritional integrity of the biomass. They strip chlorophyll, alter protein structure, and reduce the fatty acids and pigments you are buying the supplement for. We looked into post-harvest purification early on and decided against it. A cleaned-up product is not the same product. If you are choosing between one that was remediated and one that was never contaminated, the nutritional profiles are not equivalent.

How Microplastics Enter Algae Supplements

Microplastics are less discussed than heavy metals in algae supplementation, but the exposure pathway follows a similar logic. Open-pond systems exposed to the atmosphere collect airborne microplastic particles that settle on the water surface. Ponds using unfiltered water sources may also introduce waterborne microplastics.

The key difference: algae do not absorb microplastics the way they absorb dissolved metals. The particles contaminate the harvested biomass as physical inclusions, not as absorbed compounds. Sealed cultivation systems eliminate the airborne deposition pathway entirely. Filtered water inputs reduce the waterborne pathway.

No standardised analytical method for quantifying microplastics in food-grade powders exists yet. No regulatory threshold has been set. This means you cannot currently verify microplastic levels on a certificate of analysis the way you can for heavy metals. We will adopt microplastic testing when reliable, accredited methods become available. Until then, prevention through sealed cultivation is the only defence.

Prevention vs Detection: A Fundamentally Different Quality Philosophy

If you are buying an algae supplement and the company talks about purity testing, ask yourself whether they are catching contamination or preventing it. Testing is essential, but it is a net, not a wall. It catches problems after they have occurred. Prevention stops them from occurring in the first place.

We test every batch through independent laboratories for lead, cadmium, arsenic, mercury, and microbial contamination. But the testing is verification that our production system is working as designed, not a rescue operation. The difference is structural: our testing protocol confirms the absence of something that should not have been there. It does not filter out something that was.

How Contaminant Prevention Works at Phytality

Our marine phytoplankton is grown in sealed photobioreactors. We filter the water before it enters the system. The air does not contact the culture. We source the nutrient inputs to specification. After harvest, every batch is tested through independent laboratories for the four priority metals and a full microbial panel.

We described the full production process in our cultivation article. What to look for in testing documentation is covered in our certificate of analysis guide. This system illustrates what prevention-first purity looks like: control the inputs, seal the environment, verify the outputs.

What Purity Tested Actually Means on a Supplement Label

"Purity tested" without further detail is a marketing phrase, not a quality assurance standard. It does not tell you what was tested for, at what detection limits, by which laboratory, or on which batch. A product can carry the label after checking for one metal at a high detection limit on a single batch from two years ago. Technically true. Practically meaningless.

When you see "purity tested," the questions worth asking are: which contaminants, which laboratory, which batch, and at what detection thresholds? If the answers are not available, the phrase is decoration. The difference between meaningful and performative testing is explored in our traceability article.

Eliminating Heavy Metals and Microplastics FAQs

Can heavy metals be removed from algae after harvest?

Technically, yes. Acid washing and chelation can reduce metal concentrations. But these processes also damage the biomass: they strip chlorophyll, alter protein structures, and reduce fatty acid concentrations. A cleaned-up product is not nutritionally equivalent to one that was never contaminated.

Are microplastics tested for in algae supplements?

Not routinely. No standardised analytical method for quantifying microplastics in food-grade powders has been established, and no regulatory threshold exists. Prevention through sealed cultivation and filtered water is currently the only practical defence. Formal testing will follow when accredited methods are available.

What does "purity tested" mean on a supplement label?

Without additional detail, it means very little. The phrase does not specify which contaminants were tested, at what detection limits, by which laboratory, or on which batch. Ask the manufacturer for specifics. If they cannot provide batch-level documentation from an independent lab, the claim is marketing rather than quality assurance.

How does a sealed photobioreactor prevent contamination?

By physically isolating the algae culture from the external environment. Filtered water replaces uncontrolled water sources. The sealed vessel prevents airborne particulates, insects, and microplastics from entering. Controlled nutrient inputs replace variable-grade fertilisers. The contamination pathways that exist in open ponds are eliminated at the design stage.

If prevention is the priority, why does Phytality still test every batch?

Because no production system is infallible. Testing verifies that the prevention system is working as designed. It also provides you with a batch-specific certificate of analysis you can check independently. Prevention reduces what testing needs to catch. Testing confirms that prevention succeeded.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Consult your GP or a qualified healthcare professional before starting any supplement.

Methodology and Disclosure

Microplastic contamination pathways in algae cite Pereira et al. 2023 (Sci Total Environ) and Gutow et al. 2021 (Sci Total Environ). EU contaminant limits cite Commission Regulation (EC) No 1881/2006. The absence of standardised microplastic quantification methods for food-grade powders reflects the current state of analytical development as of publication.

Vendor disclosure: Phytality is the publisher of this article and the manufacturer of algae-based supplements produced in sealed photobioreactors. We have a commercial interest in the prevention-first approach being understood as a quality advantage. The limitations of current microplastic testing have been stated directly.