What did I do to my cycle?!

[sinibotia]

Well, I have a cycled (or maybe was-cycled) 20 gallon tank set up for shelldwellers. It's been 2 weeks since I moved the fish that cycled it, and I was expecting the new fish sooner, but since I haven't gotten them I added about a tablespoon of ammonia to try to keep the tank cycled. Apparently it was too much, because the ammonia went off the charts. I did a 50% water change and then let the tank sit for a while. 24 hours later, and the ammonia is gone, but now my nitrite readings (which were 0 immediately before adding ammonia yesterday) are above 5 and my nitrates appear to be in the 80 range (they were around 20 yesterday post water-change). Are the high nitrites going to cause a problem before they can be converted, or is my cycle just "catching up" after 2 weeks of inactivity? Basically, should I be worried, and should I do another water change?

 

[treemanone2003]

Without having fish there was nothing in the tank to keep things going. So you're basically back to square one. It's your choice as to how you'd like to go from here. Fish less or fish in cycle. Both if these are located in the getting started section http://www.aquariumadvice.com/forum...ou-get-started-with-your-aquarium-154837.html

As for the "other" item you stated, you should probably check this section out as well. http://www.aquariumadvice.com/forums/misc.php?do=sknetwork&page=rules


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[sinibotia]

Without having fish there was nothing in the tank to keep things going. So you're basically back to square one. It's your choice as to how you'd like to go from here. Fish less or fish in cycle. Both if these are located in the getting started section http://www.aquariumadvice.com/forum...ou-get-started-with-your-aquarium-154837.html


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But if I were back at square 1 the ammonia wouldn't have changed. Instead it went from at least 8ppm down to 0 in 24 hours, but the nitrite is really high and the nitrate got much higher than it was yesterday. So it seems like the nitrite-converting bacteria both are and aren't working, since there's both much higher nitrite and nitrate than yesterday. That's what's got me confused.

 

[enrgizerbunny]

A TABLESPOON? Look, you are in a BIG mini-cycle. This is essentially the same thing that happens to people when they add fish too fast. If your ammonia had dropped to 0 you can wait it out probably. Next time add ammonia according to either a ppm you want to reach (calculators available online for this) or just add a couple mL and do a big water change before adding fish.

Either way do a BIG water change to drop those nitrates before you add your fish.
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[dalto]

Yeah, a tablespoon is a decent amount of ammonia for a 20g tank.

I actually think adding the ammonia was a good idea. Maybe a little less. But your biofilter wasn't ready to handle that much ammonia. You essentially are creating an overlarge bio-filter which is neither a good thing or a bad thing.

Just do a nearly 100% water change right before you put the fish in. Also keep an eye on your pH.

 

[Mebbid]

Yeah, if im not mistaken a tablespoon of ammonia is enough to dose a 125g tank up to 4ppm. You just used too much ammonia is all.

 

[sinibotia]

Someone told me 1/2 a cup per 50 gallons, so I thought I had dosed lightly! Oops! In any case, I'm not too worried about a ph crash- the tank has sand and rocks that buffer the water and our tap water is insanely hard to begin with.