Our Aquatic Community (Tank)

[2ndhandsoul]

We have a 20 gallon freshwater aquarium, currently with a rainbow shark, blue gourami, and two glo-fish (a yellow and red). This has been our most stable population, so far. We've introduced a few other glo-fish that haven't made it. Not sure why. The two we have now are survivors from two different "batches." They stay at the top and are extremely active and too much for the other two fish to keep up with, I think. I think that's why they've lived so well, so far. They occupy a place in the tank the other two big ones don't always hang out and are just too swift to corner or grab. The gourami is the undisputed boss of the tank. He's harassed any other fish we've since introduced, regardless of size or type. We had a couple tiny neon type fish that basically became a three-day snack item. We then also had some scissortail fish that did well for a time, starting with five and eventually going down to three and then two. Now not sure if they are hiding or eaten. Eventually the gourami left them alone, but I think they may have wandered into the shark's domain and got pounced. The shark always seems so mellow and content, munching around the bottom and side and in various decorations. I've seen him dash after some fish, except the gourami, of course, but otherwise just ignores everything. Amazingly, I've managed to scare out one of the tiny neon fish that I have no idea where the little dude is hiding. He's small enough to be anywhere and he's shown up at times I was certain it's been too long since he's been around to still be alive. Yet there he shows up! Anyway, that's our tank, I guess I'm just wondering if we should leave our community as it is, or add any more. I think we could use another algae eater or clean-up fish, but worried he'll conflict with the shark. Apparently, we picked two of the larger and more aggressively territorial types to occupy their respective tank-space. Also, the gourami seems only to get all up on any NEW fish that are brought in. It could care less about the fish already there. I guess they are part of his "territory" now and anything new is just asking to be picked on for a while, right?

 

[jpchin]

one thing i do when i introduce new fish is turn the tank lights out before i put the fish in and leave them out for a few hours. this gives your new fish a chance to explore the tank. also i always introduce 2 or more fish at a time so there isn't just one new guy to take all the grief if there is any.ithink with your present stock you would be safe to add a few more fish to your 20g.

 

[2ndhandsoul]

I will try the suggestion, going forward. I did try once, but it was with those neon little thingies (there were five, once). Clearly, that's a bad thing to do to fish that show up in the dark, lol.

Are there any other species that you or anyone else suggest might stand the strongest chances of making through the tanks "hazing rituals?" Bigger? Small? Medium? Would another algae or bottom feeder stand a chance, as well? The gourami is very visibly aggressive, while the shark is definitely more stealth.

 

[jpchin]

Freshwater & Brackish Compatibility Chart
Tropical Fish for Freshwater Aquariums: Dwarf Gourami Labyrinth Fish
Tropical Fish and Aquariums Compatibility by Name

here are a few sites to help you make a decision on what fish to add to your aquarium. also an information sheet on the dwarf gourami. i have 7 in a 45 gal. they all get along so your's with the attitude might just need a companion?

 

[Billbug68]

I would think your problem is from the rainbow shark... Have you seen him chasing other fish a lot? 20g is probably to small for him, he's probably terrorizing everyone to death...