So You Impulse Bought a Betta Fish

Your friendly guide to fish-in cycling and not killing your new friend with his own waste products

(Originally written by u/Shills_for_fun, modified and updated by the r/bettafish team)

What is "the cycle"?

The nitrogen cycle is something a lot of betta owners are not really educated on prior to stumbling into betta ownership. What this refers to is the conversion of ammonia to nitrite and nitrite to nitrate by beneficial bacteria (and archaea). These bacteria will occur naturally in environments with these chemicals. Ammonia comes from waste, generally, whether from fish waste, dying/decaying organisms or plant matter.

Ammonia and nitrite are toxic to fish even at low levels. Nitrate is toxic as well, but mostly over the long term at mid-range concentrations (10 ppm or more), but over 20ppm is considered immediately toxic. Ideally we introduce fish when no ammonia or nitrite are present, thus not exposing them to these things. To achieve this, we create a nitrogen cycle by "feeding" the empty fish tank for 1-2 months. This is mostly done by dosing ammonia.

...uh oh

So you have a fish in an aquarium and you didn't cycle the tank. Maybe some 16 year old kid at Petsmart told you that you just let it run for a couple days. Regardless of what happened, you are in a situation. You don't want your fish to suffer, so what do you do? Your options are:

1. Take the fish back until the tank is cycled. You can find more info about cycling here. If you don't want to put a lot of work into the tank, this is the best option. If you don't mind putting work into it, you love your new little buddy, and taking him back would be a death sentence (i.e., you bought him at Walmart), then you have another option.

2. Fish-in cycle. Most people have little personal experience with this and the only image that is conjured up is a fish rotting to death in a cycling tank. Like any hobby, advice is sometimes just parroted around regardless of personal experience. If you're willing to put in the labor, this is possible, but we have to say that it's never guaranteed to be completely safe. It's also probably pretty expensive if I check my credit card statements. Anyways, this is what you'll need/do:

   • Seachem Prime - This is the water conditioner you should use. Yes, it's like 3x the cost of BettaSafe, but it's worth every penny. It's also heavily concentrated and will last you a long time. Where BettaSafe takes 7 drops/gallon, Prime takes 2 drops/gallon (1ml per 10 gallon.) In addition to dechlorination and removal of chloramine, Prime also binds low levels of ammonia and nitrite. While it doesn't remove it, it can keep your fish from suffering from ammonia poisoning during the cycle, but not without copious...
   • Water changes. Daily or every other day, 1/3 to 1/2 of the water depending on the ammonia concentration. Change it every time it gets above 0.25ppm to be safe. Again, we're letting Prime fight off low levels, but we can't let it go crazy! You will be testing the water daily with...
   • API Freshwater Test Kit. Not the strips, the liquid kits. For accuracy. And economy. Trust me, with a fish-in cycle, you'll blow through test strips anyway. But finally, you should consider...
   • Bottled bacteria. This gets the cycle going quicker. This is kind of important because without adding the BB (bottled or from BB-containing media), your cycle may take months. That's a long time to religiously slave over a fish tank. Seachem, SafeStart and Dr. Tim's are brands that are known to have working bottled BB. Of course, seeding the tank with cycled filter media will work even better, since you're certain there are bacteria.

And always remember, don't wash your filter, decorations, or gravel with tap water. If you must wash them, swish them in your dirty tank water after a water change. Tap water has chlorine which will kill your BB! Generally speaking, you should only change your filter media when it starts falling apart. Your filter media will outlast almost any fish in the tank!

If this seems daunting, well I’ve got news for you - it is! Owning a pet is a lifetime commitment and isn’t without its difficulties. It’s also very rewarding, however, with benefits that many find outweigh the trouble of adding food and changing the water. With proper care and maintenance, your little fella will provide you with years of companionship and entertainment!