I just learned about cycling but I already have fish. What now?!

[HN1]

Did you listen to the local store employee and run your filter for 24 hours before adding fish? I did and like you, I now know the error of my ways. So what to do after you put fish in the tank and then learn about the need to “cycle” your tank? What is cycling anyway? I don’t even own a bicycle!

Ok… in a nutshell and at the very basic level, cycling a tank is allowing bacterial colonies that consume harmful compounds to grow to a level to keep your fish healthy.

The first bacteria to appear consume Ammonia (NH3) and excrete Nitrite (NO2).
The next to show up consume Nitrite and excrete NitrAte (NO3).

Both Ammonia and Nitrite can hurt fish long term or be deadly on the short term.
Nitrate (NO3) is less harmful and fish can acclimate to it. I prefer to keep my levels under 20 PPM, but up to 80 PPM can be fish safe.

Where does the Ammonia come from?

Your fish produce it in their waste and any left over food (or rotting plants) decompose into Ammonia. A fishless cycle, which is preferable by most standards, involves adding an ammonia source (usually a decaying shrimp or pure non-scented ammonia) and allowing the bacterial colonies to grow before fish are added. But what if you didn’t know about any of this before buying those gorgeous fish?

This is the point that a lot of folks (including me) start to get a bit overwhelmed. There’s really no need for it though. Get a liquid test kit (API Master FW is my favorite) and follow the directions. Don’t waste your money on test strips. They are more expensive in the long run and a lot less accurate. The test results will tell you what to do. If Ammonia or Nitrite equal .25 PPM or higher, it’s time to do a water change! Remember to use a good dechlorinator, like Seachem’s Prime. If you measure .50 PPM and do a 50% change, you will be at .25. Do another 50% change and you’ll be at .125, etc.

Ok, well that’s all well and good but I already have fish! What should I do now?!

Seriously think about returning some or all of your fish and doing a fishless cycle. There’s a great sticky on it here… http://www.aquariumadvice.com/forums/f15/fishless-cycling-for-dummies-103339.html. If you absolutely can’t bear to part with your new finned friends, it’s time to roll up your sleeves and get dedicated. TEST your water daily (or more) and change it as needed! You may need to do this more than once a day so don’t be surprised. This regimen shouldn’t last longer than a month or so. Despite perpetual rumor and misinformation, changing water WILL NOT slow down your cycle and will keep your fish healthy. The bacteria that we need for a healthy “cycled” system live in the filter media, gravel, and décor, but don’t really exist in substantial amounts in the water itself.

Can I do anything to speed things up?

Yes! Get some nasty old filter media (Filter pad, bioballs, biowheel, etc.) or a handful of used gravel from a healthy established tank and put it into your filter or a filter sock in your tank. This will “seed” your system with the bacteria needed and significantly speed up cycling for you.

How do I know when my tank is cycled?

Your Ammonia levels will gradually give way to higher Nitrite levels. Nitrite will lower to zero and Nitrates will start to rise. When you consistently test zero for Ammonia & Nitrite and have increasing Nitrate, you have a cycled tank! (Woohoo!) Remember that each fish you add will add more Ammonia and that time should be allowed for the bacteria to catch up. Add slowly and responsibly and you will enjoy the hobby even more and your fish will thrive.

Happy Fishkeeping!

[happygirl65]

Very well said.

[Squareheads]

so does that mean i still have to wait for my nitrate and nitrites to spike?

:S

my tank has been running for 2 weeks. ><

[severum mama]

Originally Posted by Squareheads

so does that mean i still have to wait for my nitrate and nitrites to spike?

:S

my tank has been running for 2 weeks. ><

More than likely. Without a test kit for ammonia, we can only assume that you are somewhere in the ammonia spike phase still.

[Squareheads]

so that means it may take weeks, months, or even years for that matter in order for the ammonia spike to break in?

can't I avoid it? . . . will regular water changes help avoid it?

[severum mama]

Originally Posted by Squareheads

so that means it may take weeks, months, or even years for that matter in order for the ammonia spike to break in?

can't I avoid it? . . . will regular water changes help avoid it?

Weeks. That's the way it goes whether you cycle with fish or fishless. You can't avoid it but you can mitigate the damage to fish by doing water changes. A test kit is important because it essentially tells you how much and how often you need to change water, as well as gives you an approximate idea of where you are in the cycle. Once your tank has cycled, ammonia and nitrite will read 0, and you'll have nitrate that accumulates in between water changes. This means that your bacterial colonies have grown to a sufficient size to support the bioload that you have; i.e. the ammonia that your fish produce is broken down to nitrite, and the nitrite is broken down into nitrate. Your water changes at that point will dilute nitrate and dissolved organic compounds, and you can generally back them off to once a week.

I'd suggest reading the above post again, and then searching the articles section for other info on cycling. This is something you'll need to have a really good understanding of.

[mgamer20o0]

invest in a test kit so you know whats going on in your tank. if not just keep doing daily major wcs for several weeks.

[Squareheads]

I'll invest in the near future... I need to get my studies straight so I can finally get this final lap done and I'm gonna look for a job so I can buy more stuff for the fish... and also invest in my other hobbies, which is pretty pricey too ><

Hopefully My parents would approve of another tank in the near future

[Fromthelbc]

i ended up with a very used filter that had tons of gunk in it... within the first week my levels were good....

[tony1021]

what do you do if you have too much nitrate?