I have been trying to get my tank back on track after a huge amount of food was accidentally knocked in and threw the cycle off. I've been doing everything by the book, reading all I can on the nitrogen cycle and testing every day. I have 1 oscar and 1 catfish left, lost an oscar along the way sadly.

After 3 months of water changes, testing, etc. - NOTHING. Not a hint of nitrites and ammonia levels beyond 8ppm. So 2 days ago I was so frustrated on decided to remove the filthy filter media(mesh)- and put in new ones just to see if it was beyond dirty. I know this is against advice but in any event, the next day I FINALLY had my first reading of nitrites!!!! I was so happy to see that and assumed my tank finally had moved to the next phase of cycling. BUT...

I just got home and tested the water - and the nitrites are GONE, ammonia 8+. I am beyond frustrated and despite all my reading and buckets of water changes, I am at a loss and ready to give up. PLEASE if anyone knows what is happening here help save my fish (and my sanity)!!!!

Ok Hun, I am going to go out on a limb here and explain what I would do. you have nothing to lose.

I would place the fish in a bucket. Keep air on...

I would vacuum that tank, until all waste and extra food are gone. Wash your filter, and start all over. If that means you wash all the rocks then go for it.
Essentially what you would be doing is starting over. This way you can control your situation with water changes and cycle the tank. Your Ammonia will never reach 8.

This is what I would do... Just my 2 cents!

Forgot details:

Tank: 55g
Filter: HOB 2 mesh filters w/carbon
Ammonia: 8
Nitrites: 0
Nitrates: 5

thanks, yeah I'm thinking that is what I need to do. Any idea why I would see Nitrites for one day and now gone again? Would too much ammonia actually kill off the nitrites that had formed?

I have no idea. But in my opinion you are fighting a losing battle...

How large are your water changes?

You could try doing LARGE water changes.. Like 50 or 60% to see if that drops your Ammonia.

Been doing huge water changes (50-70%) often by the next day ammonia right back up. Been using ammo lock or amquel every couple days to try and keep my 2 guys alive.

Yea, then I would strip it and start over... Either get some good bacteria from a friend to have an instant cycle,(another option would be to check with your LFS to see if you could get some BB from them.) Even if you get BB from someoone, I would strip the tank and clean EVERYTHING really well.

Or daily water changes through the cycle. that would be 30% EVERYDAY till it is cycled. That will take about 5 weeks.

Hope this Helps.

Hi mako, i would have given up after 3mths ))) just a few questions and a few more ideas to help you out.
1, whats in the filters? sponge? media balls/tubes/floss/other?
2, do you know the output of the hob? or model so I can check.
3, No the high ammonia will not stop nitrites from being produced. its down to your filter not working/insufficient media/media dirty/or flow rate not enough.
4, whats your PH please? the PH will affect how deadly the ammonia is to the fish.

5,, I would do a very large water change. i wouldn't recommend more than 50% as a rule but it may be worth it in your case. also a few other products. the first is "prime" and " Hagen cycle". ammonia lock you already have.
6, feed very little every 3 days about 5 pellets per fish.
change 50% or more of the water.(you may need to carry out a few water changes over a few days or even wks) give the gravel a very good vacuum to remove any crap. you can make a DIY vacuum from a drinking water bottle and hose. cut the bottom off the bottle and fit the hose to the screw cap part of the bottle. add "prime" to the new water and "Hagen cycle". this should get the tank started and speed things up. or as Nicki suggested empty the tank and start again.

I notice you have 5pph nitrate. can you test tap water for nitrate so we know if your filter is producing nitrate or if its from the tap water.

please let me know what the output or model hob you have also the media you have inside as the filter will not cycle if the media is beyond use or isn't enough to cope with the flow and crap produced by the fish.

I'd strip the tank, clean it all, check on the filter capacity to make sure it can cope, clean all the media, then get a few sponges or some filter media from a known cycled tank and squeeze out into your filter to start it going.. if there are ammonia eating bacteria in the filter/tank they will take care of things..

hope this helps a bit..

T

p.s. personally i try and avoid any chemicals, and would deffo replace the carbon with more bio-media, definately..

I would do as nicksue says, and give up and start again. Dont forget to keep using the ammo lock

I would say the reason you are not getting much nitrates is cause either you have very little filtation or you filter isnt running very well. Makes sure that the filter has a good flow out of it, also you need filtration rated for a tank twice as big as your tank. Example if you have a 55g tank then you need filters rated for 110g

Thank you everyone for your advice. I decided to start over, which I of course was reluctant to do after all the time & effort I had spent. Once I emptied the tank and cleaned everything, I realized I never would have gotten that tank to cycle the way it was. Under the gravel was absolutely filthy and I was fighting a losing battle. I was following advice not to disturb things while waiting for nitrites to form but I think there was too much waste in there to overcome!!!

Thanks again everyone

i use a hose with a soda bottle with the bottom cut off, attached to it.
I let the water drain by gravity, while i push the bottle in to the gravel.
The dirt will stir up inside the bottle and be evacuated during the waterchange from the gravel, upto the bottom of your tank..
Mind you i got a 180Gl and the vacuuming still needs to be done everyweek in my case...