• Identify different types of algae and microbial films.
• Safely remove algae from glass, hardscape, and substrate surfaces.
• Adjust lighting and hydration to prevent excessive algae growth.
• Maintain clean, visible viewing panels without chemicals.

Lesson Content

Algae and biofilm are extremely common in dart frog vivariums due to:

• high humidity
• bright LED lighting
• nutrient-rich substrates
• constant moisture

A small amount of algae is natural and harmless — but heavy growth can block light, smother mosses, or make glass difficult to see through.
This lesson explains how to control algae safely and prevent it from taking over the vivarium.

1. What Causes Algae in Vivariums?

Algae thrives when three conditions are met:

1. Light
2. Moisture
3. Nutrients

Dart frog vivariums contain all three.

Common sources include:

• bright plant lighting
• overspray from misting
• nutrient-rich substrate leaching upward
• standing water in drainage layer
• excess feeder fly waste near the glass

Early algae is normal. Excess algae indicates an imbalance.

2. Types of Algae & Biofilm

A) Green Algae

Most common type; forms a greenish film on glass or hardscape.
Harmless but unsightly.

B) Brown Algae (Diatoms)

Often appears in new tanks.
Brownish dust-like coating.
Usually disappears as the tank matures.

C) Biofilm / Slime Layer

A thin, glossy layer caused by bacterial colonies.
Normal in high-humidity systems and eaten by springtails.

D) Cyanobacteria (rare)

Blue-green slime that spreads quickly.
Smelly and dangerous; requires intervention.

3. Is Algae Dangerous to Frogs?

Generally: no.
Algae itself is not harmful.

However:

• heavy algae can smother moss
• can block light from reaching plants
• may indicate excess nutrients or excessive lighting
• can make maintenance harder
• cyanobacteria (rare) is harmful

Healthy tanks show small patches of algae, not dense mats.

4. How to Remove Algae from Glass (Safe Methods)

Never use chemical cleaners — frogs absorb everything.

Safe cleaning tools:

• algae scraper (plastic only; no metal)
• credit card edge
• microfibre cloth
• terrarium-safe razor blades (ONLY on glass, never acrylic)
• moss ball (for gentle scrubbing)

Cleaning method:

1. Scrape gently from top to bottom.
2. Wipe with a damp microfibre cloth.
3. Repeat weekly or as needed.

Avoid saturating the substrate with runoff — use minimal water.

5. Removing Algae from Hardscape

Light growth:

• leave it — harmless
• microfauna often graze on it

Moderate growth:

• remove wood and scrub under warm water
• allow to dry for 24–48 hours
• reintroduce slowly

Heavy growth:

• reduce lighting intensity
• increase ventilation
• lightly scrub the surface in-tank
• avoid bleaching — unsafe for frogs

6. Preventing Excessive Algae Growth

A) Control Lighting Intensity

Algae thrives under intense light.

Solutions:

• reduce LED brightness to 60–80%
• raise the light 3–6 cm above the lid
• reduce photoperiod from 12 hours → 10–11 hours

B) Reduce Nutrient Leaching

If substrate nutrients reach the glass:

• increase leaf litter coverage
• avoid over-misting
• ensure drainage layer is functioning

C) Improve Ventilation Slightly

More airflow = less trapped moisture on the glass.

D) Wipe Condensation Early

Condensation collects organics → feeding algae.

E) Avoid Overfeeding

Excess fruit flies leave waste that feeds algae.

7. Cyanobacteria (Rare But Important)

Cyanobacteria is the only genuinely dangerous microbial film.

Identifying it:

• deep green or blue-green patches
• slimy texture
• strong smell
• spreads rapidly
• forms sheets rather than dust

Remove immediately:

• scrape out affected sections
• increase airflow
• temporarily reduce misting
• replace leaf litter
• add microfauna heavily

If it returns, remove plants and bake hardscape — it can be persistent.

Key Takeaways

• Algae and biofilm are normal in high-humidity bioactive systems.
• Green and brown algae are harmless and manageable.
• Clean glass using safe mechanical methods — never chemicals.
• Reduce light intensity or photoperiod to control algae.
• Cyanobacteria is rare but must be eliminated quickly.