Cycle/Mini-cycle question

[AmyCleary]

I've got a new 65 gal. SW tank that I started 1/4/03. I cycled it for two weeks with a bit of water from a well-established tank. I then added three yellow chromis (one big guy and two little ones), one peppermint shrimp and one small blue crab, all at the recommendation of my fav fish store.

I have been carefully testing the water every few days, and was seeing a gradual increase in ammonia, as expected. Then, I didn't test for a few days and next found that about a week ago, my ammonia had dropped to zero. My nitrites are at 0 and my nitrates are at 5.

I think I experienced a mini-cycle, meaning the tank has adjusted to the bioload, but I'm not sure.

I'm very patient, and I'm willing to wait to add anything else until I have to, but if it has "mini-cycled", how do I get the ammonia to spike again, or do I need to make a change (add another critter), to get it to happen? I don't want to add anything that might end up dying or might end up injuring my Chromis (which are already pals of mine...!)

I read religiously and have both The Conscientious Marine Aquarist and Saltwater for Dummies, but neither addresses the mini-cycle issue.

Any suggestions?

Thanks!

 

[Boogiechillin]

Hi Amy, welcome to AC! You shouldn't have anything alive in the tank while it is cycling, especially not invertebrates like the shrimp and crab. Damsels/chromises are tough enough to usually survive a cycle/minicycle, but inverts can't take it.

I would temporarily return the livestock and cycle the tank from scratch. Look in our marine archives for the thread labelled "Fishwhisperer's fishless cycling method". You performed a best a small, inadequate cycle on the tank. Water from an established tank isn't going to do much good as most of the bacteria that you are looking to culture during the cycle aren't free-floating. A handful of substrate or a piece of rock is a much better start. Also, using the damsels to cycle doesn't prepare your tank to accomodate larger bioloads - as you said, it makes for a "mini-cycle" that isn't adequate.

 

[Kiwi]

Hi Amy I have a 60 tall tank and have been waiting patiently for it to cycle now for 5 weeks. I check it twice everyday and I haven't even had a slight amonia rise or anything. It seems to be producing tones of green and brown algea on the glass yet not one spike of anything. So don't feel bad you aren't alone! I am finding this frustrating as there isn't much info where I live and I am unable to even hire an experienced aquarist to help me out. I suppose we will have to work it out ourselves. If I find out anything I'll let you know and vise versa please! Have a great day! Bye!