February '02 - Matt Hetzler's 100 Liter Brackish Paludarium. (USA)
As always, it's a great pleasure for me when I get the opportunity to show a different kind of setup from the ones featured so far here in this section. Many people write to me complaining "why only planted tanks?" "why only cichlids?" "why don't you show such and such type of setup?" and so on, but the thing is that I show what people submit to me! If a tank is a good example of proper setup and the photos meet a minimum quality level (unfortunately many submissions fail on one of those two requisites) I'll be glad to feature any and all types of setups here...*especially* the less common ones.
So, for this month we feature a very interesting and uncommon type of setup, that simulates the regions where freshwater rivers meet the oceans, and the water becomes partially salty (brackish). As you may guess, in nature such "intermediate" places are quite rare compared to the sum of all freshwater and saltwater bodies, so brackish tanks and the fish that can live in them are equally rare. But this month's tank is made even more uncommon by its owner Matt Hetzler because he took an extra step towards providing a natural habitat and created an upper paludarium for it! Why? Because one of the classic fishes that inhabit brackish tanks are the so-called asian Archer Fishes (Toxotes spp.) which have the very interesting habit of "hunting" insects on low hanging leaves and branches by "spitting" on them and forcing them to fall onto the water surface! So the paludarium allows Matt to throw in some live crickets (if you're lucky you can buy these at your local pet shop), and watch the show as his Archers display their natural behavior.
Green Spotted Puffer and two Archer Fish
Besides the curious Archers, several other species naturally inhabit at least part ot their lives in brackish waters, and are suited for such a setup: Puffers (Tetraodon spp.), Mono's (Monodactylus spp.), Scats (Scatophagus spp.), Bumblebees and other Gobies, Colombian Sharks, Orange Chromides, all Livebearers (Guppies, Platies, Mollies) and several others I'm certainly forgetting now are available in the hobby, and are either totally at home or can easily adapt to brackish waters. But keep in mind that just because they can live in the same water doesn't mean they're compatible! A Puffer will hapilly tear a Livebearer apart if it can. Another limitation of brackish water is regarding live plants, most species are simply incapable of surviving in such an environment. Note that Matt made extensive use of plastic plants to overcome this difficulty, but he's got at least one live species in there: Java Fern. Vallesnerias are also known to adapt to brackish water conditions as well. Brackish tanks will usually have their pH set between 7.5 and 8.3, moderate to hard water (10 - 20°dH), and a salinity that can vary anywhere from pure freshwater (1000 ppm) to pure saltwater (1025 ppm) but is more often kept closer to the freshwater side, like 1005 ppm. Fluctuations in salinity and other water parameters are not a problem since they happen all the time in natural brackish waters, and some say it should even be done on purpose in brackish tanks.
In conclusion, although a beginners will probably find this type of setup too restricting for their urge to bring home all the cool new species their just getting to know, a more experienced hobbyist may find a brackish tank a perfect twist to his mainstream tanks. As a culmination of this type of setup, last year I learned that in a perfectly done brackish tank it's actually possible to keep plants AND corals together! (see tank #4 in the August'01 page here in this section)
If you'd like to submit an aquarium for Tank of the Month, just contact me.
Full view showing the upper "Cricket-arium"
Photos taken by Matt Hetzler, and displayed here with his with permission.