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Correcting a cycle................

2K views 8 replies 3 participants last post by  Kaitlyn 
#1 ·
Hello and welcome to the wonderful world of fishkeeping! I would like to take a moment and talk to you about how to correct your tank cycle, if you ever have to do so. Say you cycled your tank when you first got it, you had fish in it for however long they lived, then you decided to just keep the tank running without fish in it for a while, with some water changes here and there. Now, after a while of not having fish, you decide to get back into fishkeeping, and have some fish in your tank. The first step you have to do is test your tank water, so you know the tank water parameters. I will actually use mine as a guide for you.

I have a 5.5 gallon tank that I have just kept running with some water changes here and there, nothing too spectacular. It has been this way for a year since Blue Moon passed away. This month I decide to get back into fishkeeping and I talk with several people who are knowledgeable in fishkeeping. I did a water change before testing the tank water. I tested my tank water on December 16, 2016 and the water parameters were: ammonia .25ppm, nitrite 0ppm, and nitrate 20ppm. Left it alone and got me a new betta, I have posted a thread about it, the next day. I got the betta so that I can get my cycle better, I like doing fish in cycles because then I don't run into any spikes with the ammonia or the other chemicals. After I got the betta, left the tank alone for a couple days until December 19, 2016. I tested my tank water again and the results were: before the water change: Ammonia .50ppm, nitrite 0ppm, and nitrate 40ppm. Did a complete water change. As I did the complete water change, I put the betta in the cup he came in. Got the water change done, waited an hour before putting the betta back in the tank. I noticed that I had forgotten to turn the filter back on, so I turned the filter back on and at this point it had been an hour already, so I check the temp in the cup where I had the betta with my finger and his water in the cup was cold, had to put him back in the tank. Waited a few hours before I tested again. Test results were: ammonia .25ppm, nitrite 0ppm, and nitrate 5ppm. So now I wait another three days before testing again. Today I tested my tank water and the results are: .25ppm, nitrite 0ppm, and nitrate 5ppm. Not sure if that is good or not, but I am happy that nothing has spiked. Found out that the results being the same for three days means that my load is really low and that I need to keep testing but wait a little longer in between tests, which is actually good. When you have water parameters like I got after just letting your tank run for a year without fish or food source, your cycle fell back, it didn't die. Bacteria don't die, they survive. When a cycle falls back, the nitrate keeps going up and all that is needed to get that down are water changes. When you lose your cycle, ammonia and nitrite will spike and the nitrates will either also spike or be unchanged.

When I got my betta, he didn't eat for a couple days, this is normal as he was settling into his new home. After a couple days in his new home, he started eating. The betta I got is a king betta and I need a name for him. Been calling him Baby since I got him, but I need a name that suits him.

Once your cycle is back in order, keep up with the water changes to keep your levels low, do not let them get even a little bit high.
 
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#2 · (Edited)
I would not advise a complete water change, ever. The shock to the fish and the tank is too much, especially for very fragile critters like shrimp. I would recommend 50% water change maximum in the future, to prevent shock from things like pH differences (tap water has a lot of CO2 entrained from agitation, which affects the pH) and also temperature differences.

You're right that bacteria do not die, however keep in mind that bacteria aren't like mammals - they don't die, but they do break down in the presence of toxins, infection (bacteriophages), or trauma. Enzymes stored within the bacterium release and digest the bacterium, sort of a self-consummation. What bacteria DO do is go dormant, and depending on how long they're dormant, they may take awhile to re-activate again.

Also, fish-in cycling is dangerous and potentially fatal for the fish you put in there. Excess ammonia and then nitrite are toxic to fish, and if left unchecked will cause burns on the fish and can kill them, or shorten their lifespan. I never do fish-in cycling, I've always done fishless cycling (see the sticky at the top of this forum), and I've had great success using plants, Tetra SafeStart (bacteria starter), and used filter media when I can get it.

Lastly, when using the API Liquid Titration Test Kit, keep in mind that these kits have a history of a 0.25 ppm false positive on the ammonia test. When you see 0.25 ppm ammonia, you are actually seeing bonded ammonia, which is not as easily digestible by bacteria as free ammonia. So when you see 0.25ppm, you are actually seeing NH4+ (ammonium, relatively non-toxic), you may in fact have 0ppm free ammonia, and your cycle could stall.
 
#3 ·
A complete water change, 90-95% doesn't affect the cycle in the way of harming it. Most, if not all, your bacteria are on the filter media, the other bacteria are on the decorations, gravel, etc. As long as the bacteria don't dry out, then you are fine.

There are fish which can withstand spikes in ammonia and nitrite. Bettas, for example, can withstand spikes in ammonia and nitrite, it takes a lot for bettas to succumb to spikes in ammonia and nitrite. Always use hardy fish when cycling and recycling your tank.

If you keep the water parameters in check, then you don't have to worry about any dangerous spikes that would harm the fish. I had success with cycling my 5.5 gallon tank with Blue Moon. I would do fish in cycle because then you don't have to worry about spikes in the ammonia level.
 
#5 ·
There are fish which can withstand spikes in ammonia and nitrite. Bettas, for example, can withstand spikes in ammonia and nitrite, it takes a lot for bettas to succumb to spikes in ammonia and nitrite. Always use hardy fish when cycling and recycling your tank.
That's why many people say fish-in cycling is inhumane - you're intentionally subjecting a fish to a hostile environment and justifying their suffering by saying "it's ok, they're tough."

That's like putting a human in a smoke filled room, and saying it's ok because they're tough. They're still inhaling smoke, regardless of how tough they are.

Also, the article you quote is unreliable - 1.) The site hasn't been updated since 2012, 2.) There are no quoted sources.

I'll do some research over the holiday season and find some good reading material, if you'd like.
 
#7 ·
Which is no different than if you have ammonia spikes during a fish-in cycle.
 
#8 ·
Which is why you need to keep up with the testing and water changes so the spikes don't happen to where they harm the fish. With a fish in cycle you can also watch the fish. Which in my case right now, I have to do, before I test again and do a water change if necessary.
 
#9 ·
I nearly lost a betta due to a sudden nitrite spike a few years ago. Poor thing turned brown and was lying on his side gasping when I found him. He recovered pretty much instantly with a water change, but I'll personally never cycle a tank with fish in it again for fear of that happening. Bettas are hardy, sure, but they don't always withstand ammonia and nitrite spikes.

I fishless cycled my new 5.5 gallon tank a few months ago using fish food (couldn't get my hands on bottled ammonia). I tossed in a handful of gravel and some marimo balls from an established 10 gallon, added more fish food and tested the water every couple of days. The whole process took about 3 weeks - about 5 days to get ammonia to appear and another week after that to get nitrite to appear. I did I think three water 50% water changes, one in the middle of the cycle and 2 to get all the food out when I was getting ready to add stock. There haven't been any spikes since then. This is merely my personal experience, but I found the fish food method to be way easier and safer than cycling with fish.
 
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