Wow! Nitrite spike!

[gfink]

Well, after an increadibly slow ammonia build up to 0.5 ppm. (this took about 6 weeks), the ammonia plummeted to zero and nitrites shot up to between 2 and 5 ppm (hard to tell with color cards) in two days.

I just did a 10% water change to help ease the stress on the little guys. I'll keep a close eye on it and dilute it further later tonight.

Two questions.

1) How frequently can I do these 10% water changes so that I don't overstress the fish? I mean high nitrites are bad, but lots of water changes are stressfull too. I was thinking about maybe one every 12 hours if needed to control the spike. Any input?

2) Does anyone here disagree with this quote:
"Nitrite is an order of magnitude less toxic than ammonia. Thus, one common saying about tank cycling is: ``if your fish survive the ammonia spike, they'll probably survive the nitrite spike and the rest of the cycling process.'' However, even at levels above .5 ppm, fish become stressed. At 10-20 ppm, concentrations become lethal."
Source: http://faq.thekrib.com/begin-tests.html


29 Gal
5 Zebra Danios
2 Sunburst Micky Mouse Platties (who eat all of my diatoms and algea)

 

[Mofo2713]

1. I would recommend changing 25-35% daily instead of 10%.

2. The nitrite can be just as deadly. In my experience, they (the fish) can last through the ammonia stage, but then the nitrite sucks all the oxygen out of the water and a lot of the time this can be the final straw. Of the fish deaths I have had, most of them come during the nitrite stage.

 

[workfortheman]

A good place to mention: fishless cycling? !

 

[MarkLehr]

You don't mention your pH. Most people are unaware that Ammonia is more toxic at higher pH levels & Nitrite is more toxic at lower pH levels. If your pH is above 7.4, then I would not worry at all about the Nitrite. This is probably the reason most people are able to prevent Nitrite deaths by changing water, because water changes in most areas will help buffer the water and keep the pH a bit higher.
Bottom line, a daily water change shoudln't be needed if your pH is in the mid 7's or higher.
If your pH is low, then it is panic time & Nitrite should be consider just as dangerous, and possiblty more so, than Ammonia. A daily test of Nitrite and careful observation of your fish respiration habits will let you know if your water changes are adequate. I would consider 50% daily in this case.

 

[pkremer]

hehe! No, now would not be a good time to mention fishless cycling...there are already fish in there, and I don't think gfink wants to use his bathtub to hold his fish until the tank fishless cycles...

I know it might seem like a water change every day would be stressful on the fish, but it isn't as stressful as living with high nitrite. During one of my unintended nitrite spikes, I did a 33% water change every single day until the nitrites came down, and my fish are still fine months later. Just make sure the water temp is as close as possible to the water in the tank, and that will alleviate some of the stress.

Something interesting to watch for...as you pour clean water into a tank with detectable nitrite, often the fish will come and sit right where the water is pouring in and swim through the stream of the water coming in...at least mine did.

Paul

 

[Menagerie]

Add in some aquarium salt to help with the nitrite poisoning and do daily water changes of 30%.

 

[gfink]

Hey guys, here's the update.

The initial spike occurred when the ammonia munching bacteria finally took up residence. They quickly processed all of the ammonia creating the nitrite spike. What surprised me was that the ammonia levels which were always low produced a relatively high nitrite concentration when converted. Maybe the chemical reaction of one ammonia molecule yields 2 or more nitrite molecules. (I'd rather not dig out my chem book and work out the balanced reaction) Maybe my test kit gave a false high.

Well I did a 15% water change which brought the nitrites down to 0.5 ppm where they stayed. I did a few more 10% changes over the next few days and it was easy to control.

Then I found out my lfs has biospira so I bought some (expensive) and dropped it in. Tada! Ammonia zero, nitrites zero.

So, in summary. I picked hardy fish in very small numbers to start. Kept an eye on all parameters. Fish saw one moderately bad day of nitrites. There was no gasping for air or anything like that. Since I was so careful in keeping the levels low, the cycle time took around 8 weeks before I found some biospira and just finished it off. FYI...the nitrite part of the cycle was the only part that require me diluting the system at all. The ammonia was very well behaved.

Next tank I will try a fishless cycle so I can do it faster.

 

[pkremer]

Actually, with BioSpira, there is no need for fishless cycling. That is the whole point of BioSpira, drop some in, put the fish in, you're done!

Paul