EVO 13.5 Cycle Question

[dmankin]

Hi folks. I am setting up my first reef tank, and would like some of your thoughts on my initial nitrogen cycle. The tank is a Fluval EVO 12 (13.5 gallons). I have live sand and live Pukani rock. I took my 1st readings the day after the sand, water & live rock went in, allowing the water to clear first. There are no fish, corals or CUC present yet – just sand, rock & water.

From that reading on, it seems as if the cycle was moving forward, since there were levels of ammonia, nitrate and nitrite present. As you can see in this matrix, my ammonia dropped to zero recently, and the nitrites are coming down a bit. This morning, the nitrates jumped up.

Man, I have trouble distinguishing colors to the chart from a 3-dimensional, opaque test tube!

There has not been much evaporation that I can see, considering it’s been about a week, but the salinity reading crept up, so I will do a RODI top-off to try to bring it back down to 1.026.

I don’t see any signs of diatoms on the sand or rock. The Pukani is so varied in the way of looks, it might be starting, but I don’t see it yet.

Questions:

Do I do a water change now to bring down the nitrates?
Or should I wait for the nitrites to come closer to zero before a water change? (no livestock, so I’m not worried about harmful levels at this point).

With the ammonia at zero, and the nitrates skyrocketing, is my tank technically cycled?
Would it be ready for CUC after a water change?

I’m really excited to get things in this tank, but know I must be patient. I would appreciate any input, thoughts or guidance.

Thanks,

Dave

 

[ialol]

I would wait till everything stops fluctuating it sounds like you are still going through your cycle just be patient let everything stabilize and once the cycle is finished you can do a water change.

 

[dmankin]

I would wait till everything stops fluctuating it sounds like you are still going through your cycle just be patient let everything stabilize and once the cycle is finished you can do a water change.

Thanks! That is my gut feeling as well, but that sudden jump in nitrates this morning had me wondering what was happening. I appreciate your suggestion.
Dave

 

[nautical_nathaniel]

I would also try to get a better test kit, those API kits have some issues with accuracy sometimes. Salifert or Red Sea are two great alternatives. I find the color scales on those kits easier to distinguish as well.

 

[dmankin]

I would also try to get a better test kit, those API kits have some issues with accuracy sometimes. Salifert or Red Sea are two great alternatives. I find the color scales on those kits easier to distinguish as well.

Thanks - I had that thought as well. I've read that the API kit isn't exactly the best to use.

 

[nautical_nathaniel]

Thanks - I had that thought as well. I've read that the API kit isn't exactly the best to use.

It's good for reference stuff though, like monitoring the development of your cycle like you are doing. Just not for post-cycle stuff where you're going to need more accurate readings to track stability of water parameters with. Notice how the Nitrate scale is almost exponential in increments haha

 

[dmankin]

And just like that... diatoms!