I just can't seem to get the Nitrite levels down in my aquarium. I started up an 10 gallon aquarium back on December 2 for a single 4-5" goldfish. I had brought this goldfish in from my pond to treat it for fungus on its gill cover. Since I started, I had treated with PimaFix (two seperate treatments of 9 days each time), MelaFix, Aquarium Salt. This goldfish is finally almost totally healed (fungus long gone, and gill area almost back to normal). I'm only using the salt for treatment now (keeping it around 0.1%). And being a new aquarium I struggled with high ammonia levels for almost 2 weeks. It finally came down just after Christmas.

Now my battle is with Nitrite. Its been more than a week and I can't get it down. Its hard to tell from the chart, but I think its around 0.8 mg/L. I've been doing at least 30% water changes daily. Today I did a 50% water change and when I tested an hour later, the nitrite still hasn't gone down since yesterday. You figure it would have decrease at least a little.

How long will it take? How long can my fish stand it? Now that my fish is almost totally recovered, I don't want to lose it to nitrite poisoning. More and more, I'm regretting buying the small tank (was a bad recommendation from a pet store.) Other places I talked to said that yeah, its not the ideal size, but given that its only for a few months, it should be okay. But now that the nitrites are high and not going down I'm starting to panic.

Is a reading of 0.8 mg/L dangerously high? Should I do a 80% water change? The ammonia level is staying at 0.

Also since I'm doing so many water changes should I be adding Cycle and Waste Control more often (normally I was adding this once a week per instructions on the bottle).??

Any info to calm my frazzled nerves will help.