Alder cones: natural tannins and protection for freshwater aquariums
What are they?
Alder cones are small cones rich in humins, humic acids, and tannins. Placed in the aquarium, they gently acidify the water, give it a very natural amber tint, and create a healthier environment, similar to Amazonian biotopes, for example. Their scales also provide shelter for microorganisms, fry, and very young shrimp. In botany, these cones are called “strobiles.”
Why use alder cones in a natural aquarium?
- Protective tannins: help limit fungi and pathogenic bacteria (protecting eggs and spawns).
- Natural conditioner: gentle acidification and controlled amber-colored water.
- Well-being for shrimp and sensitive fish (killifish, etc.). Protective during periods of immune vulnerability, such as acclimation.
- Natural look: decorative cones, “blackwater”-type biotope.
- Simplicity: ready to use, with no boiling or washing required.
Who are alder cones intended for?
- Low-tech / natural aquarists seeking tannin-rich, amber-colored water with natural protective properties.
- Breeders of shrimp (Neocaridina, Caridina) and fish that benefit from tannins.
- Community tanks seeking a natural conditioner.
- Educational projects: tannin cycles, biotopes, and observing spawns.
Introduction and usage tips
- Starting dosage: approximately 1 cone per 10 liters, including ponds (adjust according to the desired effect).
- Replacement: approximately every 4 weeks. Leave the old cones in place (for shelter and natural decoration).
- Instructions: place directly in the aquarium. Do not wash or boil (tannin loss).
- Capacity: 50 cones cover a 100-liter aquarium for approximately 5 months with average use.
FAQ - Alder cones
Do they color the water heavily?
A light amber coloration, less dark than with peat. It varies depending on the dosage and time.
How do they differ from catappa?
Similar effects (tannins), but release is often gentler and more consistent with cones. Natural decomposition is also much slower.
Are they compatible with shrimp and fragile fish?
Yes, and they are even recommended for general well-being and successful spawning. The released tannins help limit fungal and bacterial infections.
Can they be boiled or rinsed?
Not recommended: you would remove some of the active compounds, which would be a shame!
How long do they remain effective?
Approximately 3–4 weeks. After that, tannin release gradually decreases. Replace or add more regularly to maintain the effect (as in nature!).
Additional information
| Detail |
Information |
| Common name |
Alder cones (strobiles) |
| Species |
Alnus glutinosa (black alder) |
| Role |
Natural conditioner (tannins, humins, gentle acidification) |
| Packaging |
Pack of 50 cones |
| Replacement |
Approximately every 4 weeks (leave old cones as decoration) |
| Tips |
1 cone per 10 liters, then adjust according to the color obtained. Do not boil to avoid losing tannins. |
| Precaution |
For aquarium use only (or in ponds). |
| Indicative weight |
11.5 g |
