Join Date: Oct 2010
Location: Victoria, Australia
I'm not being judgmental. We've all made mistakes in this hobby, and those who say they haven't, are lying.
I'm assuming by 16L, you mean a 16 litre aquarium and not a 16 gallon long (I only ask this as I have seen people refer to 20 gallon long tanks as 20L before).
Unfortunately, your aquarium isn't cycled and is massively overstocked. A tank this size would have been fully stocked with a single betta. Neon tetras need to be kept in groups of at least six individuals, and in spite of their small size, they are active fish that do better in tanks of at least 40L/10 gallons. They are also extremely sensitive to poor water quality and are recommended for established aquariums because of this.
A Bristlenose pleco will quickly outgrow a tank of this size, and being large waste producers, will cause problems with water quality in uncycled aquariums.
The presence of a bubblenest means very little. It's something of a fallacy that a bubblenest means a betta is healthy and thriving.
Is it possible for you to return the other fish to the store you purchased them from and keep only the betta? Even if there were no issues with aggression, a tank of this size is not suitable for either the tetras or the pleco.
With a tank this size, I don't think there's really much you can do to stop your betta from chasing the remaining Neon Tetras apart from removing either the betta or the tetras from the tank.
I meant to ask, did you purchase any water testing kits? As you are undertaking a fish-in cycle, you need to know what your parameters are. Ammonia and nitrite can kill fish in only trace amounts, and even if the water looks 'clean', it doesn't mean it is safe for fish.
Last edited by LittleBettaFish; 06-10-2018 at 11:09 PM.