Adding leaves and other natural décor seem to be becoming an acceptable pastime for aquarists now that we're beyond the stigma that objects had to come directly from an aquatic store to be aquarium safe, writes Nathan Hill.
Pollywog Frog Farm offers a wide range of terrarium and paludarium gear which I’ve been investigating for suitability in the aquarium. My current favourite is most likely the Savu Pod.
These are seed pods from the Cariniana legalis tree, known locally as Jequitiba, and from the same family of trees that produce the Brazil nut.
They rank as some of Brazil’s oldest trees at more than 3,000 years.
The pods come in three sizes and sink about 12 hours after entering the water.
I found nothing in the botanic or medicinal world that hinted at toxicity fears with these pods, aside the inherent effects of humic and tannic acids to some animals. Savu Pods are no use to keepers of alkaline species.
The amount of tannin leached is initially remarkable, but my carbon dealt with most discolouration inside a week. As for effects on water chemistry, it’s hard to say as I already have so many other acidic elements to the tank. Safe to say that these will influence pH downwards.
Records show that extracts of Cariniana have an antibacterial effect and chemicals derived from Savu flesh have been seen to inhibit both Flexibacter columnaris as well as some Aeromonas types of bacteria, so potentially there are health benefits in the same vein as almond leaf or alder cone use.
Even better, once the pods do sink and stay down, they make perfect caves for spawning dwarf cichlids and ideal boltholes for smaller catfish.
The pods currently come in two sizes, though I suspect that more will eventually follow, depending on demand.
Verdict
They represent wonderfully natural-looking décor for the South American fan, but they haven’t been used widely enough yet to ensure complete safety, so tread carefully. Although my experiences show no adverse symptoms on fish, something, somewhere may react badly to them.
Price: Three-pack medium pods £4.50, five-pack small pods £4.99. More info from pollywog.co.uk.
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.
Don't forget that PFK is now available to download on the iPad.