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 and excrete Nitrite. The next to show up consume Nitrite and excrete Nitrate . Both Ammonia and Nitrite can hurt your fish long term or short term (deadly). Nitrate is less harmful and fish can acclimate to it. Up to 80 PPM can be safe for your fish.
Where does the Ammonia come from?
Fish produce it in their waste and any left over food/rotting plants decompose into Ammonia. A fishless cycle, which is preferable by most standards, involves adding an ammonia source 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 beautiful fish?
This is the point that a lot of people start to get a bit overwhelmed. There’s really no need for it though. Get a liquid test kit and follow the directions. Don’t waste your money on test strips as 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. If you measure .50 PPM and do a 50% change, you will be at .25.
If Ammonia or Nitrite equal .25 PPM or higher, it’s time to do a water change. Remember to use a good dechlorinator. If you measure .50 PPM and do a 50% change, you will be at .25.
I already have fish, what should I do!
Think about returning some or all of your fish and doing a fishless cycle. If you absolutely can’t bear to part with your new finned friends, it’s time to 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 misinformation, changing water wont 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 or a handful of used gravel from a healthy established tank and put it into your filter or 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?
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! 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. Beware this isn't just a hobby it's an addiction!
