About a week ago I thought I finally had my 10g tank cycled (fishless): ammonia was at 0, nitrites were at 0, nitrates were around 30. I did a water change (probably around 66%) and, because my tap water has ammonia, waited 24 hrs to test again so that the nitrifying bacteria would have time to neutralize the tap ammonia. Anyway, I tested again the next day, and found that I had a nitrite reading. Over the next few days the nitrites continued to increase until eventually they were back at 0 and I had a high nitrate reading.
So again, I did a water change and tested my parameters the next day. And yet again I found I was getting a nitrite reading. My nitrites are continuing to rise.
Why is this happening? It is like my tank is going through a mini cycle every time I do a water change. Does this mean it's not cycling properly? Does it have something to do with the ammonia in the tap water? I honestly have no clue what is causing this but I'm afraid my poor fish will never be able to move into his big tank!
How long have you been cycling the tank
What is the ammonia level in your tap water
When you do a water change are you vacuuming
What kind of filter and are you doing anything with the media with the water changes
What are all your number now for ammonia, nitrite, nitrate, pH
What kind of testing products are you using-strips or liq reagent
Are you having problems with nitrites or nitrates? I'm confused in the original post. And are you doing this cycle fishless? If you are doing it without a fish, don't change the water yet. Let it go till you get JUST nitrates.
Nitrites will be converted into nitrates, but if you're changing the water before the bacteria grows for that, then it'll never happen.
Well how long I've been cycling is a little complicated...I originally had a 5g tank that cycled in about a month, but the day it finished cycling, it started leaking. I had to get a new tank, so I decided to upgrade to a 10g. I kept all the same decorations, substrate (though I added some more), filter, heater, etc. It went through a sort of mini-cycle, taking about 2 weeks to get to 0 ammonia, 0 nitrites and 30-40 nitrates for the first time.
The ammonia level in the tap water is about .5 to 1 ppm, closer to .5.
I did use a gravel vac to do water changes.
I have an aquatech 5-15 filter; I took out the carbon filler from the cartridge and replaced it with sponge before I started up my tank. I haven't changed anything though I did swish the cartridge around in old tank water the first time the 10g "cycled" (I didn't rinse a live plant well enough when I put it in the tank, so the filter cartridge had dirt all over it.)
Today I got ammonia at 0 ppm, nitrites over 5 ppm, and nitrates between 30 and 40 ppm. I use the API liquid test kit.
McAttack: I am cycling fishless. The only time I have changed the water was when my water read 0 ammonia and 0 nitrites, but after the water change nitrites started showing up again, which is my problem.
So total time of cycling has been about 4 weeks? and the media and gravel was kept wet and aerated until the new 10g was set up, you continued to cycle.....Your number are odd especially with the nitrate, make sure you shake the heck out of the nitrate liq reagent and bang it on the table and shake it some more, the reagent tend to settle and will give skewed results.... IMO it looks like you are still cycling.....
Oldfishlady: Altogether, my tank has been cycling for very close to 8 weeks. Everything was kept wet when I changed tanks. So I'm still cycling even though my nitrite went down to 0 twice? I feel like this stupid thing is never going to cycle! Yesterday I tested and got 0 ppm ammonia, 2 ppm nitrites, and 40 nitrates. Today I tested and got .5 nitrite and 40 nitrate. I suspect nitrites will go down to 0 again tomorrow or the day after. I'll do another water change and test everything again. I'm really hoping my nitrites don't go up again but I'm not feeling too confident....
Betta Fish Bob: I really wish I could use water from another source but I just don't have the room to store several gallons of water.
UGH!!!! Yesterday I tested and my nitrites were back to 0. I changed about 3/4 of the water to bring down the nitrates and tested again today. And what did I find, but my nitrites are going up...AGAIN! It looks like they're about 1-2, it's hard to tell but they're definitely there. This is unbelievably frustrating. It literally looks like it's going through a small cycle every time I change the water, I have no idea what to do my poor fish will never move out of his 1g temporary tank: I can't put him in the 10g with its wildly fluctuating parameters!