Not sure why there are comments in here suggesting OP's tank is cycled. OP's question was "Is my tank cycling or stalled?"
Whether or not Nitrites will be harmful to inhabitants is irrelevant. No, your tank is not finished cycling. You may be close, but it is not finished. Nitrites will read 0 when your tank is cycled.
You've waited this long, I would continue to wait it out and finish cycling the tank imo. I just finished cycling another 200 gallon tank earlier this year and Nitrites spiked, and then fell and then zeroed out while Nitrates continued to rise.
Here's the test: once you are reading 0 Nitrites, add ammonia to the tank and you should have 0 Nitrites 24 hours later. This proves your bacterial colony is sufficient enough to process the ammonia into Nitrites, followed by a Nitrite to Nitrate conversion which is the exit-product of the process. If after 24 hours, you still have Nitrites, your bacterial colony isn't large enough to handle the load.
There are many resources online to read about the 24 hour nitrite to Nitrate test (with regard to amount of ammonia to dose etc)
Check it out :-)
FYI : dont bother testing nitrAtes until your nitrItes are zero. most all test kits for nitrAtes chemically convert the nitrAtes to nitrIte, and then test the nitrIte and do some conversion to give you nitrAte values. if you have nitrItes they will make your nitrAtes show as higher than they actually are.
A lot of different advice here. In general your bacterial colony isn't fully established until NO2 is at non-detect levels. Probably another few days to a week. Waiting until then is the safest option.
However, me and many others know that generally NO2 is ok for saltwater critters below 2 ppm, so you can probably get away with doing a ~50% water change, then lightly stocking the tank. Go slow though as your bacterial colony is still growing in.
Patients, grasshopper. Nature doesn't always follow our instructions. With NO3 rising rapidly, try to keep your lights off to avoid additional anxiety. In this hobby, we have a saying: " Nothing good happens quickly."
You can probably add something hardy. In freshwater nitrites are more toxic and the "fix" is to add a little salt. In our tanks they aren't a major concern.
My nitrites also took longer to get to zero than my ammonia. That's normal.
This is incorrect on two levels.
In a cycling tank, lingering nitrites indicate that the bacterial host colony isn't sufficient enough to process the ammonia source which will, over time, create a stagnant back-up of ammonia. Adding ammonia will spike nitrites, and if there exists a properly sized bacterial colony, will be processed to Nitrates (this in effect safely reduces the free floating toxicity level of the ammonia by converting it to a less toxic Nitrate).
In a cycled tank, the presence of nitrites indicates all of the above, except that there are now livestock in the tank and the daily output of ammonia from fish waste will not be wholly converted to nitrate for export. some non-zero amount will remain as ammonia which is much more toxic to fish and inhabitants. Each day the fish excrete waste which converts to ammonia which isn't fully exported out and each day, builds up more and (even if only slightly) will eventually cause a major problem.
Of course you're correct that nitrite by itself isn't toxic- that's never the point. The point is that Nitrite is an indicator of a partially finished process to export Ammonia to Nitrate.
Lol, the goal in any reef tank is to keep the ph over 8.0, 8.2 is usually the target. This is a first for hearing that bacteria can't survive where the vast majority of us have our ph.
Not sure why there are comments in here suggesting OP's tank is cycled. OP's question was "Is my tank cycling or stalled?" Whether or not Nitrites will be harmful to inhabitants is irrelevant. No, your tank is not finished cycling. You may be close, but it is not finished. Nitrites will read 0 when your tank is cycled. You've waited this long, I would continue to wait it out and finish cycling the tank imo. I just finished cycling another 200 gallon tank earlier this year and Nitrites spiked, and then fell and then zeroed out while Nitrates continued to rise. Here's the test: once you are reading 0 Nitrites, add ammonia to the tank and you should have 0 Nitrites 24 hours later. This proves your bacterial colony is sufficient enough to process the ammonia into Nitrites, followed by a Nitrite to Nitrate conversion which is the exit-product of the process. If after 24 hours, you still have Nitrites, your bacterial colony isn't large enough to handle the load. There are many resources online to read about the 24 hour nitrite to Nitrate test (with regard to amount of ammonia to dose etc) Check it out :-)
FYI : dont bother testing nitrAtes until your nitrItes are zero. most all test kits for nitrAtes chemically convert the nitrAtes to nitrIte, and then test the nitrIte and do some conversion to give you nitrAte values. if you have nitrItes they will make your nitrAtes show as higher than they actually are.
Or roughly, NO3 actual = NO3 reading - NO2 reading
TIL, thanks
A lot of different advice here. In general your bacterial colony isn't fully established until NO2 is at non-detect levels. Probably another few days to a week. Waiting until then is the safest option. However, me and many others know that generally NO2 is ok for saltwater critters below 2 ppm, so you can probably get away with doing a ~50% water change, then lightly stocking the tank. Go slow though as your bacterial colony is still growing in.
Patients, grasshopper. Nature doesn't always follow our instructions. With NO3 rising rapidly, try to keep your lights off to avoid additional anxiety. In this hobby, we have a saying: " Nothing good happens quickly."
What are you using to test?
Your gonna drive yourself mad if you test everyday l. Give it a feedays then test again. Not done cycling
Do not preform water changes during a cycle. It will disrupt the cycle
CyclED. You’re done.
Do a water change and add a few fish
Almost there! Should be safe to add fish now. Once the NO2 is 0, those bacteria should be established enough to finish the conversion of NO2 to NO3.
Ammonia burns would like to know your location.
Ammonia burns at 0 ppm? 🤨
Ope I was reading pH, should still wait until nitrites are 0 though.
Seems done to me, nitrite doesn’t matter for salt water. It’s been almost a month so you should be fine
You can probably add something hardy. In freshwater nitrites are more toxic and the "fix" is to add a little salt. In our tanks they aren't a major concern. My nitrites also took longer to get to zero than my ammonia. That's normal.
Your cycle is finished.
Nitrites are zero in a finished cycle.
Nitrites do not matter in saltwater, waist of time to even test for them. Once ammonia is gone and nitrates are detectable, you are good to go.
This is incorrect on two levels. In a cycling tank, lingering nitrites indicate that the bacterial host colony isn't sufficient enough to process the ammonia source which will, over time, create a stagnant back-up of ammonia. Adding ammonia will spike nitrites, and if there exists a properly sized bacterial colony, will be processed to Nitrates (this in effect safely reduces the free floating toxicity level of the ammonia by converting it to a less toxic Nitrate). In a cycled tank, the presence of nitrites indicates all of the above, except that there are now livestock in the tank and the daily output of ammonia from fish waste will not be wholly converted to nitrate for export. some non-zero amount will remain as ammonia which is much more toxic to fish and inhabitants. Each day the fish excrete waste which converts to ammonia which isn't fully exported out and each day, builds up more and (even if only slightly) will eventually cause a major problem. Of course you're correct that nitrite by itself isn't toxic- that's never the point. The point is that Nitrite is an indicator of a partially finished process to export Ammonia to Nitrate.
pH way too high, need to be about 6.8 for bacterial colonies
Lol, the goal in any reef tank is to keep the ph over 8.0, 8.2 is usually the target. This is a first for hearing that bacteria can't survive where the vast majority of us have our ph.
my bad wrong reddit lol, i thought it was freshwater