Nitrites not going down....

[Doug G]

Not sure exactly why, but my cycle seems to be taking an extremely long time. First my ammonia spike seemed to last a good 4 weeks as it only zeroed out about 2 weeks ago. Now its been 6 weeks, and nitrites have been off the chart for the last 3+ weeks. I'm getting worried something is wrong, I don't think this is supposed to take this long? Should have completed the whole thing in 2-4 weeks? System is a Horizon 6g with just provided filtration (cartridge/biowheel) system. Stock is 2 Neon Tetras, 1 Guppy, 1 Gold Dust Mollie.

Water is cloudy (cleaned both inside and outside of tank but no better.) I've changed the carbon cartridge twice now thinking this was the cause but no joy. Temp is 79, pH dead neutral at 7.0. Feeding once per day in AM (so I don't think its overfeeding.) PWC about once a week, ~30% to mitigate first ammonia now nitrites.

I'm concerned that the fish are being unduly stressed by this extended cycle. Am I doing something wrong? Am I missing some equipment? Is the stock bio filtration system inadequate? I keep telling myself the nitrites will go down but every few days I test and there still off the chart. Help!

[RobbieG]

The nitrite stage usually takes a while - 4 weeks sounds like a long time for ammonia but you made it.

The water being cloudy may be because of a bacterial bloom - this is a good thing.

You shouldn't clean anything else until the cycle is finished. Cleaning removes the bacteria you are tryining to grow.

Keep doing PWC's to keep the fish as healthy as you can.

If you want to try to help the cycle along get a product called biospira - its kept in the fridge at your LFS (if they have it)

[hungryhound]

Robbie is right.

i just wanted to add that in addition to prolonging your cycle by cleaning you have prolonged it by continuing to switch carbon filters. The bacteria also grows on them and removing them keeps slowing down your cycle.

Just let everything be in your tank. no cleaning no switching of filters until it is cycled. Then once it is cycled you can gradually do both.

[zackish]

Robbie is right.

i just wanted to add that in addition to prolonging your cycle by cleaning you have prolonged it by continuing to switch carbon filters. The bacteria also grows on them and removing them keeps slowing down your cycle.

Just let everything be in your tank. no cleaning no switching of filters until it is cycled. Then once it is cycled you can gradually do both.

I would agree 100% except the only thing you need to change is the water every week or so or if the levels get high. This is because you already have fish in there.

[naiku]

My nitrite spike lasted for weeks, and kept me worrying as to why it was taking so long, it only just finally dropped a couple days ago........ don't worry about it. I am just now waiting on ammonia to drop and can then do a water change and add fish........ hopefully by this weekend.

[hungryhound]

I would agree 100% except the only thing you need to change is the water every week or so or if the levels get high. This is because you already have fish in there.

Thanks for clearing that up. I do not consider water changes part of cleaning.

[Migforce]

This sounds like the problem I had. I also had a kit with a filter included. My cycle was taking forever and I could not get rid of ammonia for over six weeks. At the end the only thing that worked for me is upgrading to a bigger filter. As soon as I did that my tank cycled within two days. Bacteria need oxygen to process ammonia, so if your water is not moving fast enough it may be stunting the bacterial growth.

[Doug G]

Thanks for all the replies. I didn't realize changing the carbon filter was to be avoided. The blue fiber part on top was getting pretty grody looking after ~3 weeks and I figured it was causing the cloudy water so thats why I changed it, mfr says every 2-4wks. I thought the bacteria mainly grew on the biowheel? Of course, I haven't changed that and know it should never need to be. I haven't really cleaned my tank, just squeeged the insides in case they were dirty and creating the illusion of cloudy water. The filter system says its rated at 75gph, this is 12x tank size so from what I know this should be enough flow. Could the closed cover be preventing enough oxygen from reaching the bacteria?

I'll be sure to leave everything in place now until the cycle is completed now that I know that's the right thing to do.

[hungryhound]

Thanks for all the replies. I didn't realize changing the carbon filter was to be avoided. The blue fiber part on top was getting pretty grody looking after ~3 weeks and I figured it was causing the cloudy water so thats why I changed it, mfr says every 2-4wks. I thought the bacteria mainly grew on the biowheel?

A lot of your bacteria will grow on your biowheel but it will also grow on your filter. You may not have been removing a majority of your bacteria but you were probably removing a fair amount of it. Since bacteria growth tends to grow exponentially you kept prolonging your cycle by a little bit each time you changed the filter and Carbon.


Of course, I haven't changed that and know it should never need to be. I haven't really cleaned my tank, just squeeged the insides in case they were dirty and creating the illusion of cloudy water. The filter system says its rated at 75gph, this is 12x tank size so from what I know this should be enough flow. Could the closed cover be preventing enough oxygen from reaching the bacteria?

I doubt that. I have a small biowheel filter on a 5 gallon and it has a problem where if the water level is not at a certain point then the biowheel does not turn. I would make sure that your biowheel is turning, but as long as it is you should be fine.


I'll be sure to leave everything in place now until the cycle is completed now that I know that's the right thing to do.

That should help out a lot. Plus you sound like you are almost there anyways, so crossing our fingers it should not be too long now. Good luck

[Lady Hobbs]

The reason you're told to replace the filters every couple of weeks is because the charcoal in the filter is only effective for a couple weeks. The filter pad is still storing the bacteria, however, and that's what you need. If you need to clean the filter pad off, just wipe it off in tank water you have removed during a water change. Do not clean it off in tap water.

Chlorinated water kills the bacteria so make sure you always use a dechlorinater. A cycled fish tank for a few months can be very touchy and easily set back by cleaning too much gravel at once or cleaning the gravel and replacing the filter at the same time, etc. Once this tank has finally cycled for you, do minimal cleaning for several months.

"White Tank Syndrome" is what you have going on. As newbies to this, we think it's due to needing cleaning but, in fact, is due to being too clean already. We start working on things to correct this condition but only end up making it worse and prolonging the condition.

This is a "been there-done that" and we all know exactly where you are as we've probably all done the same thing at least once so don't beat yourself up over this.

The ammonia eating bacteria is a fast growing bacteria but the nitrite eating bacteria is annoying and seems to take forever sometimes. The tank can appear to be stuck in limbo at times. When the nitrites do finally began to disappear, they seem to go nearly all at once.

One thing that appears to help is higher water temps and aerating the tank. I would turn your temps to 81-82 and add a bubbler if you have one. Bacteria loves the heat and oxygen and grows faster.

Tank salt is often recommended when nitrites are high to help the fish with gill function. This depends on what type of fish you have as all are not accepting of salt.

You may find this encouraging but larger tanks are much easier and if you ever get a bigger tank, you probably will not experience so many problems. What you are going thru now is why we often speak of "fishless cycling" as cycling time is about 12-15 days with no worrying about the fish and no water changes needed.

Just be patient and this will all come together for you.

[Doug G]

Just wanted to say thanks to all for the the advice and "hang in there" sentiment. I did exactly as described, no filter changes, no vaccumming, etc (just one water change, tho) and about 3-4 days ago I noticed the tank was clearing out. As of yesterday its crystal clear. Last time I checked nitrites (about a week ago) they were near 0 so they should be zero by now.

I made it! (whew!)

[Lady Hobbs]

Congratulations! Patience does pay off and you have just gotten thru the worse part of keeping fish. The dreaded cycle using fish is stressful for all. Next time out, use the fishless cycle and you'll be done a whole lot faster.

Don't go too nuts adding too many fish now all at once and you'll do just fine.

[elmer]

Congrats - Now you can start checking your Nitrates and doing water changes.