Cycle

[lisa23]

Hi, I set up a new tank last week, its a juwel rio 180. I let it sit for a couple of days then added half the sponges from a mature tank filter, and on the same day 4 zebra danios.

I have been testing the water daily and haven't seen any rise in ammonia or nitrite, but a rise in nitrate, which is now at 40 ppm.

Do you think there was enough bacteria to cope with the danios and it will be ok to add a couple more in a few days, or do you think the amonia just hasnt had chance to rise yet?

oh and eventually i want to add some tetras and a catfish - as these require mature tanks how do I go about adding these? do I just wait 6 months and then add them in a few at a time, or will this still cause a rise in ammonia? if it will how can I add them and prevent that?

Thanks

Lisa x

 

[rdd1952]

How long has it been since you added the fish? What is the nitrate reading in your tap water? If it is low and the 40 ppm have obviously come from processed ammonia then you are probably fine to add more fish. I would just make sure it has gone a full week with no ammonia or nitrite before adding more. Just keep in mind that you may see s slight mini cycle when you add them.

As for the tetras and corys. I think the key thing is that the water parameters are where they need to be. A tank isn't really considered mature until it is 6 months or so old. I know you don't want to wait that long to add more fish. As long as there isn't any ammonia and nitrite, you should be fine to add tetras and corys. Just add them slowly so as not to overload the bacteria you have causing an extended mini cycle.

 

[lisa23]

The fish have been in for 6 days and the nitrate in the tap water is fairly low, well i presume it is as I tested the tank water before I added anything and it was. I don't mind waiting the 6 months if its going to make a difference to the fish, but i presume if I just wait 6 months and then add them it will still cause a mini cycle?

Thanks for your help

 

[rdd1952]

You're right, regardless of when you add them, the bacteria will have to multiply to catch. Most everything I've read states that nitrifying bacteria can double in about 24 hours or less so if you don't ever do more than double your bio-load, you shouldn't see a mini cycle at all.

 

[lisa23]

Great! thanks