Cycling Question

[jag72]

In the middle of a cycle of a new 90 gallon tank with 100lbs of dry rock that has been added. I started off by taking the ammonia to 4ppm and then added two bottles of Bio Spira to try and kickstart the cycle. After two days, the tank had pretty much 0 ammonia and the nitrites were around 8ppm with a few nitrates. Forward two days and still have 0 ammonia, under .25 nitrites and it now appears to be 0 nitrates within the tank.

With all the reading that I have done it seems strange that my nitrates would be go down to 0 during the cycle as most everybody else has a decent amount of them toward the end of their cycle. Is it possible hat the bacteria in the tank would already be established that it would be able to convert the nitrates to nitrogen gas already?

Would like some opinions on this to make sure I am heading down the right direction with the cycle as this is my very first marine tank.

 

[CodyRVA]

If you have any doubt it didn't fully cycle, add more ammonia and test accordingly. You might not have supplied the system with enough of an ammonia source, thus barely to or no nitrate.

 

[bobman]

By adding bio spira you added ammonia consuming bacteria which is why your ammonia went to 0 so quickly. You tank is technically almost cycled which is why you are seeing you nitrates going as with nitrite.

The way I like to cycle a tank differs depending on if I use live rock or dry rock.
If using live rock add ammonia but try to keep the ammonia under .025 for at least a few weeks by dosing ammonia to raise the levels and bio spira to lower the levels as needed. Only reason to keep the ammonia levels down is to keep the life on the rock alive.

If using dry rock just add ammonia and let it rip. No need to add bio spira. Once the cycle is complete and you slowly add livestock add a little bio with each addition.

 

[jag72]

Thanks for the feedback. When I seeded the tank with ammonia it took the tank to around 4ppm and it took 3 days for it to read 0ppm. On the second day I did receive a nitrite reading of around 5ppm and nitrates were showing around 10ppm. I mistakenly let the tank then continue for two more days without taking any readings and that is when I noticed that the nitrites and nitrates were .25 and 0.

Realistically if the tank is pretty close to being cycled, I should be able to add some more ammonia and it should take it back down to 0 within 24 hours correct?

I know that Bio Spira was not needed but I did want to see if it would help with the cycle process timeframe. Not sure if the reason for the quick turn of numbers was actually adding a more than is needed for my size tank and sump. I have around 120 gallons between the two and put in enough for a 150 gallons as I didn't want to just throw the leftover out. Figure the extra shouldn't hurt anything.

 

[CodyRVA]

Have you continued to supply the system with a source of ammonia? I spiked mine to about 10 ppm with pure ammonia, one way or another it will cycle.

 

[tankstudy]

Realistically if the tank is pretty close to being cycled, I should be able to add some more ammonia and it should take it back down to 0 within 24 hours correct?

Yes, as you approach sufficient levels of bacteria, it should convert all the ammonia in 24 hours.

 

[jag72]

Decided to do another dosing of ammonia and treated the water until it was 8ppm yesterday. 24 hours later the ammonia is down to 1ppm, nitrites 5ppm and nitrates >80ppm. Looks like the cycle process is moving along quite well. Figure by morning the ammonia should be gone and then will need to see the nitrites begin to drop.

 

[CodyRVA]

Decided to do another dosing of ammonia and treated the water until it was 8ppm yesterday. 24 hours later the ammonia is down to 1ppm, nitrites 5ppm and nitrates >80ppm. Looks like the cycle process is moving along quite well. Figure by morning the ammonia should be gone and then will need to see the nitrites begin to drop.

IMO it's cycled. Do your large water change to remote the nitrates and you're good to go. If you're using API test kits, mine always showed 1 ppm of ammonia, I wouldn't worry about it; the system clearly cycled.

 

[jag72]

Thanks everybody. I decided to take a water sample to the LFS yesterday to verify my new readings and all is good.

0 ammonia
0 nitrites
5ppm nitrates

Everything looked good so we brought home our first fish yesterday. We picked up a sapphire blue damsel. I know a damsel can be a bully as the LFS drove me away from the one I really wanted due to that fact. This one is supposed to be much better at getting along with the other fish that will be added over the next 6 months. Figure we are sticking with this one for the next 30 days prior to adding any others.

 

[CodyRVA]

Thanks everybody. I decided to take a water sample to the LFS yesterday to verify my new readings and all is good.

0 ammonia
0 nitrites
5ppm nitrates

Everything looked good so we brought home our first fish yesterday. We picked up a sapphire blue damsel. I know a damsel can be a bully as the LFS drove me away from the one I really wanted due to that fact. This one is supposed to be much better at getting along with the other fish that will be added over the next 6 months. Figure we are sticking with this one for the next 30 days prior to adding any others.

Good deal, and yea they can be a pain. While there are risks involved (ailments/disease) with adding another fish so soon; by waiting a while you're and giving the damsel time to take control of the tank.