Is My Tank Cycled?

[jrussuk]

Heres another fishless cycling question!!! I thought my tank was cycled eating ammonia from 4pmm to 0 in less than 12 hours nitrites went to 0 nitrates sky high. I done a 90% water change toped back up with conditioned water added ammonia up to 2pmm waited 24 hours and my nitrites went back up to .5 pmm ammonia 0 nitrates 30 ( which is normal for my other tanks as theres a reading of 20 nitrates in my tap water). So is my tank nearly cycled? I done a reading this morning and my nitrites was back down to 0 !!!! i tested my tap water and theres 0 nitrites in it. So im a little confused as ive fishless cycled a couple of tanks and have never seen this happen.
many thanks for any advice

 

[martyn413]

Hi,

I wouldn't do a 90 % water change. It may have caused your cycling to look odd. Try a 10 - 20 % water change when ammonia and nitrite are 0 then test again.

Martyn

 

[Miss Wiggle]

can't quite understand what you're saying has happened.

add ammonia to 5ppm, test 12 hrs later if you're down to 0 ammonia and nitrite then it's cycled. if not then it's not!

 

[jrussuk]

thats correct but when i done the 90% water change to lower the nitrates i added some ammonia again too keep the bacteria alive the nitrites went up again

 

[GoldLenny]

When you only dosed 2ppm of ammonia, you are starving some of your N-bacteria that you built up at 5ppm. There was no need to do a 90% PWC until you were ready to add the fish. Go back to basics, dose the tank to 4-5ppm of ammonia and see if the N-bacteria are converting it in 12 hours. If not, then keep up the fishless cycle until they are.

 

[jrussuk]

Cheers i'll do that ammonia and nirites were 0 again this morning so i dosed it up to 4pmm again and will test it again when i get in from work