Fast Cycle - How fast is TOO fast?

[Drewpenry]

Hey,
New to the hobby. This week i scored a used redsea c130 34 gallon tank with hood and stand. The setup came with a small amount of established substrate and a refugium/sump full of established filter media and several gallons of used tank water. The tank was filled three days ago and a 20 lbs bag of caribsea arag-alive was added to the existing substrate. Some dry rock was also added.

Here where i need input: 2oz of high quality beneficial bacteria were added to the tank upon filling it with correctly mixed reef saltwater. On the second day i already only had .50ppm ammonia and equally low nitrites. Day 3, zero readible ammonia or nitrities. Nitrates are at 30-40 ppm.

The tank appears to be cycled, as the beneficial bacteria product had advertised. A good friend of mine is insising i continue to wait for the tank to be "cycled"
But with established media and substrate, and zero readings on ammonia and nitrite, isnt it safe to add some snails and crabs?

I cant see why the ammoinia would spike if i simply add these creatures slowly over time, eapecially if i am already getting zero readings.

So, to wait or not to wait, that is the question.

[Daddi0]

Welcome! Personally I would say to wait. Patience is a huge part of this hobby. Good score by the way!!
Cheers! Mark

[mcgyvr]

When starting with sufficient "established" stuff you can have little to no cycle at all..
Sufficient bacterial populations are already present..
I'd suspect that the existing substrate and sump with media contributed far more to this than any bacteria in a bottle...
Hard to say for sure though from this side of the internet..

Nothing good happens fast in this hobby..

So yes you can likely slowly start stocking the tank if you think your cycle is over.. A few snails and what not could be just fine..

Or you mess up/make the wrong decision and they all die

[Drewpenry]

Thanks for he quick replies.

I am going to err on the side of caution and continue to wait. If the readings remain low then i will begin adding small critters next week.

On a side not, there is a large amount of mulm and deteriorting stuff in the filter from the owners previous setup. This debris should provide enough ammonia to feed the existing bacteria, thus preventing a crash, right?

[mcgyvr]

Originally Posted by Drewpenry

This debris should provide enough ammonia to feed the existing bacteria, thus preventing a crash, right?

Thats not something you need to worry about..
I wonder where all the new people are getting this information that you need to constantly be feeding a tank or its going to crash or something.. Thats a common belief/question lately..
The bacteria in a tank can easily go a year or more without any food input into the tank and even so there isn't going to be a crash of any sort even if there isn't more food added..
Once that bacteria train is moving there is just no stopping it..

[ReeferNoob4ever]

mcgyvr, I blame carbon dosing for this new found concern. I have heard of bio balls crashing a tank, although I don't completely understand why.

[Drewpenry]

Originally Posted by mcgyvr

Thats not something you need to worry about..
I wonder where all the new people are getting this information that you need to constantly be feeding a tank or its going to crash or something.. Thats a common belief/question lately..
The bacteria in a tank can easily go a year or more without any food input into the tank and even so there isn't going to be a crash of any sort even if there isn't more food added..
Once that bacteria train is moving there is just no stopping it..

Clearly some of my "experienced" buddies are under incorect notions about bacteria and the ammonia cycle. In my years of keepin freshwater planted tanks
I have always used established media to jumpstart new tanks with great success. I assumed it would be the same for saltwater.

The owner of my LFS is the one who sugguested the bacteria additive. The low readings of ammonia and nitrite were also found when a sample of my water was tested by them as well. Sometimes i have doubts about the accuracy of test kit. However, its reassuring to see the same ammonia and nitrite results when tested in store.

I guess my stubborn friends are going to have to re-evaluate their trust in proven testing methods.

[mcgyvr]

Originally Posted by Drewpenry

In my years of keepin freshwater planted tanks
I have always used established media to jumpstart new tanks with great success. I assumed it would be the same for saltwater.

I guess my stubborn friends are going to have to re-evaluate their trust in proven testing methods.

Using established media is fine/great and holds true for both salt and freshwater..
Thats also why local fish stores have "live rock" in vats of water.. So that you can buy it, a tank and a nemo fish and take it home and set it up all in the same day.. That established rock contains all the bacteria a tank needs so there is no cycle.. So you don't kill that little Nemo then return everything to the store the next day..
Very little bacteria is free floating in the water.. Its all stuck to surfaces like rock/sand/glass,etc...

Its just the bacteria needing to continually be fed or a crash or something will happen thats goofy to me.. thats not going to happen in both fresh or saltwater..

[Shamous113]

Originally Posted by mcgyvr

Its just the bacteria needing to continually be fed or a crash or something will happen thats goofy to me.. thats not going to happen in both fresh or saltwater..

The thought behind continually feeding a low dose of ammonia prior to introducing fish/cuc to your tank is that you are creating a larger more stable population and you’re reducing the size/potential of the mini cycle that follows adding your fish that just came out of qt. It also has allowed people to add larger bio loads to a newer system eg. adding 4 adult seahorse to a 60gal cube with no ammonia spike.

The good bacteria Nitrosomonas and Nitrospira are autotrophic, which means that they produce their own food by performing chemosynthesis using ammonia and nitrite combined with an oxygen source in order to convert these to the relevant nitrite and nitrate, and to reproduce if enough of ammonia and nitrite are present. I believe 20% of their energy is used for reproduction. They actually do go into hibernation when one of the food sources go missing or are in short supply and the populations can decrease in numbers over time. I’ve read that a time period of 4-6 months at room temperature without food and with no significant die-off has been documented (can’t remember where I read this). It takes time for the bacteria to come out of hibernation and the population is slow to grow compared to the unwanted bacteria strains. The quote below is from this source .


“Nitrifying bacteria reproduce by binary division. Under optimal conditions, Nitrosomonas may double every 7 hours and Nitrobacter every 13 hours. More realistically, they will double every 15-20 hours. This is an extremely long time considering that heterotrophic bacteria can double in as short a time as 20 minutes. In the time that it takes a single Nitrosomonas cell to double in population, a single E. Coli bacterium would have produced a population exceeding 35 trillion cells.”

The issue with feeding a tank ammonia is the level of nitrate that is accumulated in our tanks. There are 2 ways to deal with this. A large water change (80%) or carbon dosing near the end of your cycle. Carbon dosing is not something I would recommend for a beginner without a lot of reading prior to doing it.

[mcgyvr]

Originally Posted by Shamous113

I’ve read that a time period of 4-6 months at room temperature without food and with no significant die-off has been documented (can’t remember where I read this).

The study I saw suggested almost a year.. I included that above just not in my last statement..

I certainly agree that they may go into a hibernation state which is also stated by bacteria supplying companies as to how they can have shelf lives of a year or more on their products in a bottle...

Its just most think "I'm not getting fish for another week.. so I'm dosing ammonia...." so thats the confusion I was addressing..
And yes thats just going to drive their nitrate levels up which requires more work to get down post cycle..