i don't mean to be a stick in the mud, but i don't understand the species selection for this column(?). this is supposed to be a planted aquarium forum. [I]Arius jordani[/I] seems like a bad choice for a planted tank.
I hate to also be a stick in the mud, but PLEASE do your research before you purchase this all too common chain store staple. This fish is DISASTROUS in most tanks. This is mostly due to the fact that it is most commonly purchased by newbies.
This includes MYSELF. My first fish were a pair of these in a ten gallon tank. Three years later I had aquired four more and all exceeded 12". They were living in a kiddie pool because they had outgrown every tank I owned.
In addition to thier size this fish really needs to be kept in groups, and it is also a VERY active swimmer. As they mature they become very neurotic in a small tank (55 gals or less), constantly banging thier faces against the glass and occasionally spooking and attempting to leap out of the tank...no fun. Please have at least a 6 ft tank ready for these guys.
That aside...they are awesome fish! Can't beat the super cool "shark" look! Although "knowledgable" people will tell you they "require" brackish water as they mature or they will "develope skin problems" or just die, it is worth mentioning that all the larger, older specimens I've encountered have lived in pure freshwater. I'm certainly not arguing that brackish isn't thier natural environment, or that it would be best for them....it just may not be as important as people imply.
they also do fairly well in full marine. (SG 1.020 - 1.022 is what the LFS keeps them in) Not sure if this is bad for long term or not but several months and they are doing great.... better that the FW ones)
I HAVE HAD A SLIVER TIP SHARK IN A 25 GALLON TANK FOR 5 YEARS AND BOUGHT HIM A 55 GALLON TANK I HAVE ONLY PUT A FEW TABLESPOONS ON SALT IN THE TANK DURING WATER CHANGES. HE HAS GROWN TO BE ABOUT 12-14 INCHES LONG NOW HAS NEVER EATEN ANY OF MY OTHER FISH AND IS VERY WILD AND CRAZY IN THE TANK (ALSO HAS JUMPED OUT ONCE) MUST HAVE A LID AT ALL TIMES! I JUST GOT 2 MORE AS LITTLE BABIES DOES ANYONE KNOW THE MALES FROM FEMALES?
To Plopkid5, I actually have a tank that contains a dragon goby with the silvertipped. It works, though I wouldn't recommend it, and in fact regret my set-up now. Sadly, I'm kind of stuck with it for a while. The issue here is that the shark(s) is/are going to want to take the dragon goby's food, who is essentially defenseless against these guys. They're quick and strong, whereas the dragon goby is weak and practically blind, making it easy for the sharks to spot the food and difficult for the goby. I used to have a castle in my tank for the goby, in which he mainly stayed because of the darkness in it (since they like the dark). At the time, this made it easy to have both the silvertipped and the goby, because i would drop algae waffers through a tube/straw like thing. So he got his food and the shark had no idea. So if you can pull off a setting like this for your dragon goby (and make sure he mostly wants to be in that secluded area), then I say go for it. Aside from a food issue, they don't conflict or bother each other at all, from my experience.