Why Are Nitrites High?

[kajones]

I recently set up a nursery tank for my guppies as they are all heavily pregnant. It has a new filter and gravel in it but i took one of the filter sponges from my other tank and put in the new filter. It's been running for a few days now with 8 guppies in it but the nitrite levels are high, why would this be? I've been doing big water changes and adding anti nitrite treatment but no change.

 

[doresy]

how big is the tank (capacity)?

If the tank has not been cycled properly then by just adding old media it has started to digest the ammonia produced by your guppies which in turn has produced the nitrIte. The nitrIte digesting bacteria which takes longer to build up is not present in a big enough quantity from your old media hence the nitrIte reading. By adding some old media to a new filter it does speed things up but the filter still needs to cycle. Have you tested for nitrAte to check that the cycling process is completing?
Constant smallish water changes should help you through this period.


Ps (Off subject) I am afraid to have to report that the wonderful gourami (male) I took from you started to go down hill after a good start then died last night All water stats perfect so I guess it was the stress of moving etc. (they are very prone) Female doing excellently (they are very much stronger than the males)

 

[kajones]

how big is the tank (capacity)?

If the tank has not been cycled properly then by just adding old media it has started to digest the ammonia produced by your guppies which in turn has produced the nitrIte. The nitrIte digesting bacteria which takes longer to build up is not present in a big enough quantity from your old media hence the nitrIte reading. By adding some old media to a new filter it does speed things up but the filter still needs to cycle. Have you tested for nitrAte to check that the cycling process is completing?
Constant smallish water changes should help you through this period.


Ps (Off subject) I am afraid to have to report that the wonderful gourami (male) I took from you started to go down hill after a good start then died last night All water stats perfect so I guess it was the stress of moving etc. (they are very prone) Female doing excellently (they are very much stronger than the males)

Oh that's a shame about the gourami, he was a fine looking fish, just one of those things i suppose. Glad to hear the female is doing well.
The tank is only small, 8 gallons i think. I was under the illusion that putting filter media from a mature filter would equate to a cycled tank, silly me. I only rushed things because of imminent guppy birth, didn't want the fry eaten by other fish in my commmunity tank. I did a nitrate test too it's 10 mg/l which is fairly good but i imagine that will go up as the nitrire goes down if the tank is still cycling. Will the guppies be o.k or should i take some out do you think? Will these nitrite levels affect the developing fry?

 

[doresy]

having any nitrIte is bad for any fish......having nitrAte means things are on the way as far as cycling is concerned. Don't get me wrong, matured media is golddust in the fishy world but is not a miricle worker. Keep doing 20% water changes to keep the nitrIte down.

I have been trying to cycle a small 34 ltr fry tank for 5 weeks now and I started with some very mature media. My fry (gups) have been waiting to go in for some time now! Why not just keep an eye on you pregnant guppies while in your main tank and get a breeding net (about a fiver) and pop her in when she looks fit to burst. Keep the fry in there untill you other tank cycles....(remembering to add ammonia)

 

[Don Trinko]

Adding salt (non iodized) any where between 1 teaspoon per galon and 1 tablespoon per 10 galons will protect the fish from nitrite poisoning. It should not bother the guppies at all, If fact they can actualy live in salt water if done gradualy. I had the same thing happen to my Discus tank. It worried me a lot but it didn't bother the fish! It will probably take 2 weeks or slightly more for the nitrifing bacteria to catch up. Make sure you check for amonia just in case. Don T.

 

[kribensis12]

What you should do is go to your lfs, and buy a filter pad that eats up nitrite until your tank is cycled proprly.

 

[kajones]

Adding salt (non iodized) any where between 1 teaspoon per galon and 1 tablespoon per 10 galons will protect the fish from nitrite poisoning. It should not bother the guppies at all, If fact they can actualy live in salt water if done gradualy. I had the same thing happen to my Discus tank. It worried me a lot but it didn't bother the fish! It will probably take 2 weeks or slightly more for the nitrifing bacteria to catch up. Make sure you check for amonia just in case. Don T.

Thanks for that advice, i have marine salt for my brackish tank, will that do or does it need to be aquarium salt? I will pick up one of those anti nitrite pads too.

 

[scorphonic]

The reason why there are nitrites is because even though you took a "mature" filter from your cycled tank it does not always mean that the tank that you transfer it to is immediately cycled. I did exactly what you did but I had to wait at least 2 weeks before everything went to zero again before adding in the fish. Your best bet if you are to do this again is to get the filter from the new tank and leave it sitting in the older tank for a while, seed it with some old medium and it should be ready pretty quickly, at least that way there would be no nitrites or ammonia present in the new tank!