Nitrite spike

[glolite]

My 27g has been up and running for about 5 weeks. It was 'seeded' with gravel and filter medium etc., and ammonia/nitrites have been nil since the initial spike (fishless cycled). Anyway, it's had fish in for about 3 weeks and suddenly there's a nitrite spike but no ammonia. The only reason I can think of is overfeeding so have done 2 x 25% water changes today. The nitrites were 0.25 this am and it's only slightly less now. Is it worth doing another water change tonight or should I do them daily? Have also added some more used filter floss from another tank.

 

[WILDER]

How many fish did you add and which kind.

 

[glolite]

Six platies first week, then water change end of that week, 4 gupps second week, water change end of that week. Last week I added 1 pair of apistos and 2 hoplo catfish (both pairs are babies). I thought if it was a fishless cycle then you could add more fish initially then just a few weekly?

 

[WILDER]

Stocking abit fast, bacteria colony hasn't built up enough to cope with them yet.

 

[glolite]

Ok, so is it worth changing water tonite till nitrites disappear?

 

[WILDER]

Don't go mad with water changes as it will delay the mini cycle, but it want's fetching down as anything above 0.20 is lethal to fish, Can you squeeze a sponge from old tank onto the cycling sponges.

 

[glolite]

Have already put floss into filter from established tank, it's a fluval so no room for big blue sponges but the floss was nice and grubby!!

 

[WILDER]

Should be back to normal then in a day or two good luck.