Using alder cones

[Angel1837]

Hi...new to fish keeping...Q. I’ve got a fluval flex & it’s for charcoal in the filter section, it’s in a little net bag! Anyway I’ve read that alder cones are good for the general tank environment because they leach tannins etc but I’ve also read that charcoal takes out impurities in the water...so will I defeating the purpose of alder cones if I leave the charcoal in? Of have I misunderstood altogether?

 

[Lilyann]

If the tannins (stain) from Alder cones is what you are interested in getting by adding to aquarium, then the visible aspect of these tannins will likely be taken out with carbon. But, the acidifying/antibacterial properties of alder cones will still be predominately active in tank water. In other words, while some of the benefits will be taken out through carbon filtering, a good amount will not be.
But, Alder cones have many other valuable benefits beyond the release of tannins: they also provide surface area for beneficial bacteria/ biofilm and act as a surface for the development of supplementary food source for freshwater shrimp, algae eaters like otocinclus, and fish fry.

I use carbon when I first set up a tank during cycling, when I am taking out medications from water column, or have issues with suspended materials in water. But, the majority of the time a cycled, well filtered, maintained aquarium can do without it.

 

[Angel1837]

Thank you Lilyann
That was exactly what I wanted to know. The tank is 3 months old so I think I’ll take the charcoal out & see what the alder cones do

 

[seangee]

Thank you Lilyann
That was exactly what I wanted to know. The tank is 3 months old so I think I’ll take the charcoal out & see what the alder cones do

That is sensible. Throw the charcoal out and if you think you will need it in future buy a new bag. Charcoal gets exhausted after about a month and needs to be replaced to be effective.