Cycling question - unexpectedly quick nitrite/nitrate readings

[Agent Kooper]

I've set up a 12-gallon nano tank. I put in about 15 pounds of live sand (purchased in a bag from Petsmart), 15 pounds of base rock (CaribSea fossilized/petrified reef rock) and the water two weeks ago.

About a week in, I poured in a bottle of Bio Spira, just for the hell of it, and because I didn't really know what I was doing. I've been measuring the water, also just for the hell of it, getting 0 ammonia/nitrite/nitrate -- exactly what I expected because I don't have an ammonia source yet.

I decided to put in one raw shrimp to start the cycle. I did this 24 hours ago. I just measured the water and got a reading that surprised me: no ammonia (that's not the surprise, because I know I was impatient on the test), but 3 ppm nitrite and 40 ppm nitrate.

I don't know how I'm possibly getting nitrite and nitrate readings at this point -- I was just looking for the first signs of ammonia. Is it possible my live sand and the Bio Spira already started cycling my tank before I added the shrimp?

This is my first marine tank, but I've been educating myself and these results surprise me given what I've read.

 

[Ingy]

I never liked bio spira or other cycle boosters. The bacteria they add can consume ammonia and nitrites without colonizing on the rocks. That causes what I call a false cycle, because the bacteria in the water column won't all survive and only a small amount will colonize. but, it does provide a bacteria start you need. As for live sand, I have never used it and wonder how much is hype. Can the bacteria really be alive in a bag of dry sand?

 

[Agent Kooper]

I had the same question about the sand, though it was a little damp in the bag, like you get if you dig down a little bit at the beach. That's why it seemed unlikely that there would be much cycling going on in the tank prior to addition of the shrimp.

I considered the possibility that the Bio Spira is messing with my readings without actually contributing much to the colonization of the tank. But with no ammonia to feed on, I wonder how much bacteria in the Bio Spira bottle would have survived in the tank in the week prior to my adding the shrimp.

We'll see. I'm interested to see what readings I get over the next week.

 

[IslandHopper]

I considered the possibility that the Bio Spira is messing with my readings without actually contributing much to the colonization of the tank. But with no ammonia to feed on, I wonder how much bacteria in the Bio Spira bottle would have survived in the tank in the week prior to my adding the shrimp.

We'll see. I'm interested to see what readings I get over the next week.

What did the BS bacteria survive on while they were INSIDE the bottle?... And how long was that bottle on a shelf, in storage, in transit before you opened it?... I don't know that it is "snake-oil", but I'm just very skeptical of such products.
If you're concerned that the bacteria might have "starved to death" in the tank before you gave them an ammonia source, wouldn't you also expect them to all die off while sitting in the bottle for months on end??

Live sand, kept damp, will have lots of decaying material in it, providing an ammonia source for the remaining bacteria, and should be viable for months if kept moist.... In my OPINION, the LS provided much more of a boost to your cycle than the bottle of BS.

 

[begginersluck]

Was the rock dried un-cured live rock?

 

[Agent Kooper]

Was the rock dried un-cured live rock?

No. It is fossilized reef rock.