Nitrite levels - How high can they go without harming the fish?

[AquaNewby182]

I am three weeks into cycling my 29G tank..

1 Red Wag swordtail, 1 Mickey Mouse Platy and 4 zebra danios, 2 fancy guppies

Ph 7.0
Ammonia 0 ppm
Nitrite 2 ppm (maybe higher - test kit is hard to color match)

Temp 78-79 F

How high do I let the nitrites get before having to do a water change? I'd prefer to wait it out and let the biological growth take care of the nitrite but don't want to kill the fish...


Thanks

-AquaNewby182-

 

[Avalon]

Nitrite tolerance should not be a question to consider. It is harmful to fish in any amount, be it temporary stress to gill damage.

What I think you're asking is "how long can I go before my fish suffer permanent damage?"

Fish can tolerate nitrites for a short amount of time, but exposing them to it for a long period of time, like the amount of tank cycling time, could cause damage. I'm not aware of any studies that has documented evidence, so, I don't know. Risk them as you will; I guess you'll know if you have some floaters one morning

 

[Fishman_2000]

That's a kinda sketchy choice as to what to do. Nitrite takes a while to go down. If it were me I would do a 10 gallon water change. That way you almost cut the nitrite levels in half and the bacteria can eat up the nitrites quicker. I lost a few fish due to nitrite last year when I got back into this hobby.

 

[FroggyFox]

Pretty much agree with Avalon. I had 3 danios in my 10 gallon tank for three weeks...in that time the nitrite got up to "High" (where yours is haha...I think we have the same *stupid* kit) I acquired a new 15 gallon and took the danios out after about 10 days of the nitrite being high.

I guess thats not really an answer for you...Avalon put it right...I guess you'll know that they've had enough when you find a floater. Kinda harsh...but true. I haven't heard any magic number either about how long a fish can be in it before having permanent damage.

Also...in my case the nitrites didn't even go down after numerous water changes. I let the nitrites get as high as they wanted after I took the danios out...kept feeding the tank with ammonia, got too much...did a 40% change....then a 60% change...and the nitrites didn't even go down at all. It just took time.

eh..."patience patience"

 

[pyackel]

Anything below 2ppm's of nitrite is generally safe for most fish.

 

[FroggyFox]

thanks pyackel...but what about when you're cycling and it goes over 2ppm's? how long before you have to worry about the fish having permanent damage??

 

[pyackel]

good question - that i don't know - and it may be a tough nut to crack - there might be a host of other variables that effect the toxicity - for instance, adding an aquarium salt will help reduce toxicity. The chloride ion competes with the nitrite ion at the gills. When the chloride ion is present at least three times and not more than six times the level of the nitrite ion, it is preferentially transported across the gills. Thus transport of the nitrite ion is reduced. Keeping the chloride levels in the water at least 20 mg/1 can prevent nitrite toxicosis. Additional treatments can include emergency water changes to dilute the nitrite problem.

 

[tetra girl]

hey i need to get a new nitrite test kit and was wondering if i should get one that tests above 5ppm or shouldnt i bother as thats pretty high anyway?

 

[FroggyFox]

I wouldn't bother...5ppm is pretty high.

 

[pyackel]

If it goes off the scale, then make a 50/50 using tap water and your tank water - then add the reagent drops. If then you get a reading of, say, 3ppm's - just multiply it by 2. At one point my nitrites were so high I had to do 1:4 ratio of tank water to tap water to get a reading on the chart - then I multipled that reading by 4.

 

[FroggyFox]

pyackel...you are so smart! I never would have thought of that. Kudos

 

[pyackel]

well, i try - thanks froggyfox21

 

[GDH]

Your fish are all salt tolerant so you could add 1 tablespoon of aquarium salt per 5 gallons of water. It will make the nitrites less harmful to the fish. Only put the salt in once. The salt will get diluted out later during water changes.


*Edit: Someone already mentioned about the salt, I guess I should have read the replies before I posted.