Bio Layer
A Water Filter Made From Moss
Built by kids. Proven by science. For every school on Earth.
⚠️ 2.1 billion people don't have safe drinking water — and millions
of kids drink lead-contaminated water at school every single day.
⚠️ 2.1 billion people don't have safe drinking water — and millions of kids drink lead-contaminated water at school every single day.
What is BioLayer?
Nature's answer to school water pollution
BioLayer is an inline water filter that attaches to school drinking fountains. It uses three natural materials — sand, activated charcoal, and living Sphagnum moss — to clean water from the inside out. The moss is the secret: it absorbs lead and other heavy metals through natural chemistry, and it never runs out.
Who it helps
Every child who drinks from a school fountain — especially in schools with old pipes that leak lead into the water.
What makes it special
A living Sphagnum moss layer that absorbs lead through natural ion exchange chemistry — no chemicals, no electricity needed.
What it costs
Under $30 to build — compared to $90–$200 per year for standard school filters that use 15+ plastic cartridges annually.
Who can build it
Any kid, anywhere. All materials are available at a hardware store or garden center — no special tools or training needed.
Four layers. One mission.
Water enters dirty at the top and exits clean at the bottom — passing through four carefully chosen layers that each do a specific job. The clear tube lets in light so the moss stays healthy and alive.
The Science
What does each layer do?
Gravel
Spreads the incoming water evenly across the full width of the tube so every part of the moss layer gets used. Think of it like a traffic director for water.
Sphagnum Moss
The star of BioLayer. Moss cell walls have natural negative charges that grab onto positively charged lead and heavy metal particles — like a magnet. It also releases natural antimicrobial compounds that keep the water safe.
Activated Charcoal
Removes chlorine, chemicals, and bad smells from the water. It has millions of tiny pores that trap unwanted particles as water flows through.
Coarse Sand
The final layer catches any remaining dirt, sediment, and particles. By the time water gets through the sand, it exits clean and clear at the bottom.
Proven by Science
The numbers behind BioLayer
BioLayer is backed by 7+ peer-reviewed scientific studies. Here are the key facts:
Lead removed from water in just 60 seconds by Sphagnum moss (Lubbad et al., 2019–2020)
Heavy metals removed — lead, copper, cadmium, zinc, and chromium
Total cost to build BioLayer vs. $90–$200 per year for standard school filters
Plastic cartridges generated — standard filters throw away 15+ cartridges per fountain every year
Big Science Word Alert!
What is a Controlled Biological Filtration Layer?
That is the scientific name for the moss layer in BioLayer — and here is what it means in plain English:
Controlled means the moss is a known species in a sealed packet — not a random mix of microbes. Biological means it uses a living plant to do the filtering, not synthetic chemicals. Filtration Layer means it is one specific layer in the filter doing one specific job.
It is a plant, not bacteria
Unlike other biological filters that use bacterial communities, BioLayer’s moss is a plant — which means it is safer and more predictable.
It fights bacteria naturally
Sphagnum moss releases natural compounds called sphagnans that actually kill harmful bacteria — which is why it was used as wound dressing in World War I!
It needs a little light
That is why BioLayer uses a clear transparent tube — so ambient light from the room reaches the moss and keeps it healthy and photosynthesizing.
Easy to refresh
The moss sits in a small mesh packet — like a tea bag — that slides in and out easily. When it needs refreshing, just swap the packet. No tools needed.
Build It Yourself
What you need to build BioLayer
Everything costs about $30 total and can be found at your local hardware store, pet store, or garden center.
Clear PVC tube (4″ wide, 12″ tall) (Hardware store) — ~$10 2 PVC end caps (Hardware store) — ~$3 Faucet adapter (Hardware store) — ~$3 Live Sphagnum moss (150g) (Garden center / Amazon) — ~$6 Activated charcoal (500g) (Pet store / Amazon) — ~$8 Fine filtration sand (800g) (Hardware store) — ~$3 Small aquarium gravel (300g) (Pet store / Amazon) — ~$2 Mesh screens x3 (Hardware store) — ~$3
Total cost to build BioLayer: ~$38
Assembly Steps
Build it in one afternoon
Drill small drainage holes in the bottom PVC cap. Attach the faucet adapter to the top cap so it connects to the fountain outlet.
Add the sand layer
Place a mesh screen at the bottom of the tube. Pour 800g of coarse sand on top and press it down gently until level.
Place another mesh screen on top of the sand. Pour 500g of activated charcoal granules on top and level it out.
Prepare the moss packet
Rinse 150g of live Sphagnum moss gently with clean water. Wrap it loosely in nylon mesh to create a sealed packet — like a tea bag of moss.
Add the moss layer
Place the moss packet directly on top of the charcoal layer. This is your Controlled Biological Filtration Layer — the heart of BioLayer!
Place the final mesh screen over the moss. Pour 300g of aquarium gravel on top. Seal both caps and attach to your fountain. You’re done!
Why It Matters
The impact BioLayer can have
public schools in America that could use BioLayer to protect kids from lead
plastic cartridges generated by BioLayer vs. 15+ per fountain per year with standard filters
people worldwide without safe drinking water — BioLayer can be built anywhere with local materials
saved per fountain per year compared to standard school filters — money schools can use elsewhere
Want to build BioLayer at your school?
Join the Save Drop BioLayer team — build a filter, test it, and help us bring clean water to schools everywhere. Every result matters.