OK -- tomorrow will mark 8 weeks that my 55 gallon tank has been up and running.

When I started the 55 gallon I used a filter that had been running for about 5 weeks on another tank. I have Emperor 280 and Aqueon 325 filters, both stuffed with extra biomedia. I have four goldfish and one bristlenose pleco. My fish are fed fairly lightly -- 1-2 pellets each in the am, a pea each in the pm. My pH is 8.2, KH is 350+, and temperature is about 78. I had been salting to 0.1%, but about a week ago I stopped adding salt in hopes that the absence of salt would help my cycle to complete.

My ammonia has been at zero for about four weeks; it is the nitrites that I can't get rid of. When I test each afternoon, nitrite is between 0.5 and 1.0 ppm and nitrate is usually around 5.0. I change 50% of the water one day, then use AmQuel+ to bring the nitrite down the next.

I am wondering -- how much longer do I have to go?! Is it strange that my tank hasn't cycled after 8 weeks? Is there anything that I am doing that might be delaying the development of my nitrobacter bugs?

Fortunately, my fish are not showing any signs of stress, in fact they are all growing, getting brighter colors and longer fins.

Advice, please!

Actually - it is not unusual at all. FRUSTRATING, but normal. Those beneficial bacteria that process the nitrites are finicky little things - annoyingly so. It usually takes at least twice as long to get them up to speed as it does the type that process the ammonia!

I have had cycles take as long as 16 weeks to become fully cycled. I have had ones pop into existance in as little as 4 weeks (this is with NO seasoned media - just with clear ammonia).

Since you are showing nitrates (I am assuming you have none in your tap water), this means that you have a colony of the second type of beneficial bacteria that process that nasty nitrite. It just is not a big enough colony to take care of the waste that the fish are making. Those little finicky guys are kinda nice in one way, though. As soon as you get some growing, they sit around driving you crazy and then BAM they multiply and do the job. It usually happens just about the time you are ready to SCREAM. It is really close now - not much longer. One morning you will wake up and your nitrites will be at .25ppm.....and then in a few days, they will be gone and all will be shiney.

Hang in there. You are almost there.

I think I would suggest that since you do have nitrites in the tank - anything over 0.25ppm - that you should probably put in the salt to a 0.1ppm level. It does such a good job of protecting gill tissue from the nitrites - and really does not impact the development of the cycle.. not at that strength.

Thanks, Daryl, for the reply.

No, there is no nitrate in my tap water, so there are at least a few nitrobacter somewhere in that tank!

Somewhere I read that nitrite is less toxic in high pH water (in the same way that ammonia is less toxic in low pH water). Is this true?

One way or another, at my next water change I will start salting again.

Also, I am wondering what your thoughts are on whether I will be overstocked if I add my new ranchu to the 55 gallon after her quarantine is over and after I am finally cycled? That would make 5 goldfish and one bristlenose pleco -- too much?

OVerstocked is a subjective word. Yes - you would have more than the "recommended" one goldie per 10 gallons. (The pleco counts) A 55 gallon tank is not really 55 gallons - it is somewhere less. For example, if I take out 24 gallons out of my 56 gallon tank in a change, I am changing a lot more than 50% of the water! Add back in the amount of water held by a cannister filter and you get still a different number.

The rule of thumb with 10 per fish is also just that - a rule of thumb. What it is based on is a tank that will, with the least amount of work and effort, keep the goldfish kept within it as healthy as possible under ordinary circumstances.

It is assumed that you have average sized fish, feed them average to light, have at least 10 times turnover in filtration per hour, have average temperatures, average aged fish and change out at least 20% of the water at least every week.

Large fish. Single tail fish. Breeding fish. Fish with outstanding medical problems. Growing fish. Fish with outstandingly large tails/fins. All need a bit more room than "standard". You can keep more than the "standards" in a tank if you are willing to WORK for it - this means that you may have to change out 75% of the water every 2-3 days or add more filtration and change more often, or feed less, or have a different combination of fish in a tank. But it can be done. Eventually, though, the fish bear the brunt of it - and you get too many to manage.

Remember - the larger the water in respect to the number/size of the fish contained, the longer time you will have to react when and if things go sour. A heavily stocked tank can go bad quickly and nastily - and a lightly stocked tank can give you more reaction time. Fish grow faster in better water - and it is easier to keep the water well with fewer fish. Fish that do not have to compete for food or space or whatever, also grow larger and faster and better.

I have some tanks that are "overstocked". I have others that are "understocked". I have 5 in a 40 gallon tank. I have 3 in a 60. I have 6 fry in a 30. But, for the individual fish that are in the tanks and the amount of work I do on the tanks, for ME, my tanks are fine.

I guess you have to ask yourself if you are willing to up the water changes, up the water tests....etc. Test your water. Do your nitrates rise by more than 20ppm between water changes? Can you easily change enough water to keep the nitrates at or below 10ppm? Are any of your fish delicate? HAve floating problems or fin congestion or whatever?

These considerations may help you decide whether or not you can comfortably fit another fish in your tank.