Cycling Question. Is this too good to be true??
 

Well 8 days ago I put water and a cocktail shrimp that had sat dry in bucket for 2 days into my 20 gallon nano. The ammonia peaked on day 3 and the nitrates appeared. Yesterday, I noticed the nitrates had fallen from the previous day which peaked around 0.8 mg/l, so I threw in the first live rock and 3 hermits. Today I just tested and the nitrates are almost non existant. I have had fast cycles before in FW tanks but only when seeding filter media. My question is: is this too good to true? Did I somehow screw up? I don't have a nitrate kit yet ( I wasn't expecting to need it so soon) I'm hesitant to start adding any fish or delicate livestock in case the test results don't reflect the truth.

Ken, cured live rock is like an instant filter. And if you just had an empty tank of water with a shrimp, it wouldn't be a lot anyway. If you have LR and no NH3 or NO2, you're fine.

Thanks Brad, I had some (dead) sand in the tank and I knew the LR would have bacteria, I just thought that was too fast. But given your input, I guess a trip to the LFS is in order today!! Some more rock and a royal gramma may be on the menu!! Thanks again.

Usually you would cycle the tank with Live Rock and sand. This could be why it only took a short time.
The LR you purchased will cycle again. If you bought it as Cured LR the cycle will be very short. But I would feed the tank again and maybe get the Hermits out of there as you will see another spike

J

If the LR is cured from the LFS and you don't live far, it won't cycle again. And hermits are more than capable of handling a bit of a spike. Hermits are often used in cycling a tank.

Live Rock from store tank to my tank 15-20 minutes in watered bag. I don't think there was any die off. In fact the few baby feather dusters on the rock seem to extend more often in their new home though I fear for them as I understand they need an established aquarium to survive. I thought hermits would be a good idea to add incase any shrimp "debris" was still in the tank and I heard they were tough.

Ken, your plan seems sound, and the rock will be fine for that distance and time if kept wet. Good luck! I would get the rock setup first though, before adding a fish. Just so the tinkering you'll do doesn't stress it :razz:

I'm with Brad. No problem for the rock but I would wait even a week or more to add a fish. Much better chance for a gramma to survive.