Ok so you got yourself a new fish tank. You got the perfect gravel, the decorations to accent the theme your going for, so the filtration, your food, nets, chemicals, and EVERYTHING else needed to keep a fish alive in a box. So what’s next? That’s right, the fun part. Buying fish. This last step can be the most rewarding… But also the most painful, money consuming, frustrating, stressful part of an aquarium and knowing these tips can save you hundreds… Sometimes thousands of dollars worth of dead fish and lost dreams.

 

First things first, a BARE BONE BASIC understanding about the nitrogen cycle.

 

1. When you add fish into an aquarium, like any animal they poop and pee. That’s right, fish pee! And just like with humans, that pee has ammonia, or NH3, which can and will kill a fish. Luckily for us natural bacteria forms in the aquarium over time that can break down the toxic ammonia and turn it into nitrites or NO2 (pay close attention to the I in nitrites because it can get a little confusing). This nitrifying bacteria usually takes about 2 to 3 weeks to fully overtake the ammonia.

 

2. But we’re not fully safe yet since nitrites are toxic to fish as well! Again luckily for us ANOTHER nitrifying bacteria breaks down the nitrites and turn them into nitrates, or NO3. This second nitrifying bacteria also can take up to about 2 weeks to fully overtake the nitrites. Only when both ammonia and nitrites are out of a tank tank can you be sure your aquarium is fully established and ready for more sensitive fish.

 

So how do you cycle your aquarium without unnecessarily murdering fish? Here’s the sad part…. Not all fish are created equally. Some fish are sensitive to the slightest amount of ammonia and nitrites, and others can survive levels so high I’d compare the water to nuclear waste. Here are a few dos and don’ts when choosing a hardy fish to start your new aquarium.

DO:

• Most barbs (keep in mind they are mostly semi aggressive)
• Danios
• Tetras: Lemon, black neon, sarpae, blood fin, prestilla, von rio, bleeding heart, candy cane, glow, skirt, emperor, black phantom (these can be peaceful to aggressive dependent on the specific species)
• Most cichlids (almost always going to be semi aggressive to fully aggressive)

DON’T:

• Any loaches
• Tetras: neons, cardinals
• Angel fish
• Discus
• Gouramis
• Plecos
• Rainbows
• Barbs: dennisoni,

       

Of course there are more, but for the sake of time I’d say if you have any questions ask your lfs for the sensitivity of fish you aren’t sure of. Lastly purchasing bacteria supplements like Stability, microbacter, nite-out 2 or Dr tims can rapidly speed up the nitrogen cycle. But always remember to test your water weekly, or before purchasing any fish.