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FAQs on Establishing Nutrient/Biological Cycling in Marine Systems, Science/Rationale

Related FAQs: Establishing Cycling 1, Establishing Cycling 2, Establishing Cycling 3, Establishing Cycling 4, Establishing 5, Establishing Cycling 6, Establishing Cycling 7, Marine Cycling 8, Marine Cycling 9, Biological Filtration, Marine Cycling 10, & FAQs on Biological Cycling: Techniques/Methods: Seeding Filter Media, Live Rock/Sand, Using Livestock, Cycling Products: By Manufacturers/Names: Bio-Spira, Cycle...  Chemical Feeding, Anomalies/Fixing 1, Trouble/Fixing 2, & Fluidized Beds, Undergravel Filters/FiltrationDenitrification/Denitrifiers, Ammonia, Nitrites, Nitrates, Phosphates, & Nutrient Export,

Related Articles: Establishing Cycling, BioFiltration

Mmm, stable, optimized conditions, introduction of beneficial microbes, sufficient substrate and food... and time going by...

help me understand... Using ammonia exogenously to cycle marine sys. More reading    3/10/14
Hi Bob,
Sometimes I enjoy hypotheticals and seeing how they would translate to theoretical applications. I have probably 500 hrs, if not more, reading about water chemistry, and the nitrogen cycle.
When one starts a new tank, say 100 gallons, and ghost feeds a shrimp to start bacteria, there really is no way of knowing how much ammonia will in turn be created by that single shrimp. (same with flake foods, pellets
<Actually; there's a pretty easy way to get close... think of how much protein... weighing... bomb calorimetry even... and how much amino bonds there are in AAs>

So if they did, and the tank cycles in a month, and they then add a clownfish, and still have 0 amm. and 0 nitrite. Its safe to say the bio load was able to handle the clownfish. Now you add a yellow tang, and again, a 0,0 reading. So basically you climbed two steps of the bioload latter.
<Not necessarily; no>

In theory, if a person wants to have this tank, with say five, four inch fish, that for example, any given day produce 25 ppm of ammonia. Would it not be wise, to allow the tank to cycle, with pure ammonia, and the amount the bacteria are going to be called upon to handle?
<No... too much NH3/NH4OH overwhelms the capacity/life to metabolize...
Just search this>

 This way, when you get your zeros, you will know the bacteria was able to
consume enough ammonia that the fish would have produced had they have been
I ask because a lot of people I talk to, become discombobulated when it
comes to fish selection and order of fish. If one wants an aggressive fish,
and wants to add it last, and at that time, the first passive fish they
added, dies, well then there whole hierarchy of fish is ruined. Meaning if
your first fish was a passive wrasse, and dies, you now have a sohal tang
that may not accept that replacement wrasse after the sohal.
Does this make sense? I guess one last way I can try to convey my idea is,
if you, Bob Fenner, wished to setup a 1000 gallon tank for one fish, a
banded cat shark. If you cycled the tank with ghost feeding, and it cycles,
it becomes zero amm. and zero nitrite. You then add a damsel, then a clown,
to work your way towards handling the bioload of this particular shark.
This may take a year, and in the end, you have fish you now have to
Rather than gradually climb with ghost feeding, and live fish, would you
not be better off, adding pure ammonia in the tank, to simulate what this
given shark is going to produce when it finally goes into the tank. This
way, the bacteria in the tank have adjusted handling and consuming the
larger waste load? Seems to me that is not only efficient, but more
practical because in the end, the fish you built with are not going to be
in the end result tank you wished to have.
Please let me know if this in theory is correct, which in turn I feel will
give me a better understanding of bio loads and nitrogen cycles.
Thanks, Bob 

Belize System Zero Exchange    2/15/13
Have you ever heard of a Belize System Zero Exchange system based on heterotrophic rather than autotrophic bacteria? 
<Mmm, yes; have seen up-close/personal in Belize itself, read of over the years... developed commercially in the early 90's>
 I don't understand the science but supposedly this bacteria goes straight from Ammonia to biomass rather than going through the nitrate cycle.
<Well... a bit of oversimplification. Actually some of this heterotrophic pathway goes on in aquariums, particularly ones that are purposely "fed" carbon>
 I was curious if this is just freshwater (lots of references to commercial aquaculture on Google) but then at the same time there are references to marine shrimp ponds -  I assume that's saltwater??? 
<Brackish to marine; yes>
Curious if such a system would work for a marine aquarium?
<It does indeed. Do Google the string "Belize System Zero Exchange system based on heterotrophic rather than autotrophic bacteria" and read a bit re... the commercial application can be applied to small captive systems.>
<Thank you for sharing. Bob Fenner>

Using a U.V. Sterilizer during cycling a tank   2/6/10
Hey Bob, I have a quick question for you. Does using a UV sterilizer during a tank cycle ( fish only with no live rock or freshwater tank) slow down or inhibit the cycling process? Thanks and I hope to hear from you soon.
<I think this would be an interesting (scientific) experiment to conduct.
Celebratedly, the bacteria involved in Nitrification reside on hard surfaces... not in the water column where they'd be readily exposed to the UV over time... but the UV does much more than "zap" such life... among other notable effects such irradiation raises RedOx and DO... maybe reducing the populations of water-suspended microbial life
enhances/decreases establishment... I suspect that having, running a UV might well shorten the time of establishing biological cycling. Bob Fenner>

New Tank Syndrome Hi there... <Greetings from David D!> I've been reading through you web site for some time now, and you seem so willing to help people... That's hard to find in any hobby. <Helping people is the reason this site exists! we actually enjoy doing this this!>  Any suggestions you can give would be great!  <Okay>  I started my first fish only salt water tank about 4 weeks ago.  It is a 45Gal. pentagon corner tank.  The tank was left to run for two weeks with no fish, I fed the empty tank as some books have suggested to start the cycling process.  <I would have just added live rock. No feeding. It will prolong the cycling process.>   I'm using a Proquatics canister filter that is rated up to 60Gal tanks.  The temperature has been steady at 78 Degrees F.  Is this a stable temperature for marine critters?  <78 degrees 24/7? Fantastic! Many experts would suggest this as the optimal temperature for most tanks.>   Specific Gravity is between 1.021 and 1.022. <Would be better between 1.023 ad 1.025...No biggie.>   PH has been at 8.6, this seems high since most books say PH should be between 8.2 and 8.4 <Correct. But PH is a dynamic reading that will change at different times of the day or night. Try testing PH at different times of the day. If it's at or above 8.6 all the time, you are on the high end of the scale. I would not feel comfortable with the PH going any higher.>   Is there any danger of  PH being this high?   <See above>   If so, what can I do to bring it down to the "recommended" range?  <Are you adding any supplements to this tank? Water changes will lower the PH unless the new water is also at a high level! Test the water before adding to the aquarium.>   Alkalinity is also high.  <Test your makeup water and water used for changes. The problem is most likely your tap water.> Unfortunately the chart I have just has low, normal and high readings... no numbered readings. <You need a new test kit.>   Is it dangerous for Alkalinity to be this high, and if so what can be done to bring it down.  <Without a number, I don't know how high you mean.>  After the two week period I followed the suggestion of a store sales person to use damsels as starter fish to help along the cycling process.  I added three small damsel fish, and of course two just died. <Likely high ammonia and nitrites. This problem could have been avoided if you had used live rock instead of damsels. This would have avoided the damsel sacrifice to the ammonia gods.> the other is still ok, but is becoming a little more lethargic.  <He's probably going the way of the dinosaurs!>   The day after I added the fish I tested the water with a Red Sea Marine Lab, ammonia was at 0.25ppm (toxic ammonia 0.05),  <That's way, too high.>  nitrite was at 0.2, <needs to be zero to be healthy for fish>  nitrate was at 2.5 (true level 0). I just check all of this again, after two weeks and now the amounts are: ammonia 0.5 (toxic ammonia 0.1),  <Must be zero. Keep waiting. No water changes until cycling has finished>   nitrite 0.2,  <See above>  nitrate 5.0 (true level 3).  I can see here that the cycle is in its process, but before I add any more fish and kill them off, when do I know that the cycle is complete?   <When ammonia and nitrates remain at zero for a week or more.>   I have read conflicting ideas of when the cycle is done.  <This is pretty standard in the hobby. Patience...>   What readings will I get from this marine lab kit that will tell me its done, and safe to finish stocking the tank?  <See above. Always stock slowly, one fish added every two weeks or more.>   One book says to do a 100% water change when the cycle is done (doesn't this defeat the purpose of waiting all this time to let the tank mature?)  <Not if the cycling is finished. Your are waiting for the inevitable buildup of good biological bacteria. But I wouldn't do a 100% water change. If the water tests perfect, I would do a normal water change like 10-20%>   Other books have said to do a 50% water change when its done cycling... What do you recommend? <See above>   I also think I may not be aerating the water enough.  I have one airstone at the bottom corner, and the air pump is at full power.  Will this be enough to keep the oxygen level ok?  more airstones?  <Try a bubble bar (wand). It gives a nice bubble wall effect.>   I have one power head in the tank circulating the water, I tried to use the air hose that came with it, but it produces so many tiny bubbles, that the entire tank becomes cloudy with bubbles.  <Don't bother with the air hose.>  So I decided to just use the power head to circulate the water.  With a Fish only system, do I really need a protein skimmer?  <For optimal fish health and long term success? You certainly do!>  As for this canister filter I have, will other forms of media in it help things along?  <Yes but be diligent in changing and cleaning the media.>  I've seen these small cylinders that claim to help bacteria cling to them, keeping the stock of bacteria high.  Do you suggest any other media other than the carbon  <In the filters? Use whatever the manufacturer recommends. If this were my tank, I would add live rock some time before the cycling process finishes. If you get good quality, fully cured rock, it won't interrupt the cycling process at all.>   Well, I think that about addresses all of my questions... sorry there are so many. <Absolutely no problem> Thank You in advance! Justin <My pleasure Justin. My friend, if you really want to be successful with this venture, and save a lot of wasted money, buy a couple of good saltwater aquarium books. The Conscientious Aquarist (by Bob Fenner) comes to mind as well as many others and continue reading on WetWebMedia. You're on the road to success!>  

Est. Biol. Cycling I am in the process of cycling my 100 gallon salt water tank. I add some live rock to cycle the tank. for two weeks I had an ammonia reading of 2 part per million, then it dropped to 0.5 parts per million. Is this normal when cycling with live rock. All the tanks that I have cycled before would go from high and then just drop to zero. I'm I doing something wrong? Thank You, John Bugby <No, you just have not waited long enough. -Steven Pro>

Re: Cycling Question Thanks Steven! The salinity is at approx 1.18. Is it possible that the low salinity may be delaying the bacteria from forming?  <Yes, absolutely> The bacteria that creates Nitrates from Nitrites? Was thinking of keeping the water temp at 78 and bringing the salinity to 1.24 <A good plan. Bob Fenner> Thanks again! Bill

Cycling Question Hi there! <Cheers, my dear. Anthony Calfo in your service> I am new to this and so I hope you will forgive my question if it seems a bit absurd.  <the way I dress... I would never think anybody else absurd> I understand that you must cycle a tank first and that it is possible to have several "mini-cycles" afterwards. But what I was wondering is this - Let's say that you have no fish in the tank (don't want to kill anything, so in my hypothetical world we won't have fish in the tank). If the ammonia spikes up, and I didn't do a water change, will the normal cycle of then ammonia goes down as nitrites goes up followed by nitrites go down as nitrates goes up still occur?  <yes... if/when a culture of nitrifying bacteria have been added/inoculated and assuming that there was some source of fuel/food to cause the ammonia spike in the first place. Some folks that want to cycle their tanks without fear of killing fish will inoculate the tank with a handful of gravel from another established aquarium or purchased bacteria and then feed the tank ammonium chloride for 2-4 weeks to feed and supercharge the blossoming biological filter (colony of nitrifying bacteria). At the end of the trial, they do a big water change and then stock the tank with fish> I only ask because I'm trying to understand the "biology" of the water system. Is "cycling" something that happens only once when the tank is set up,  <generally, yes... and occurs again (as cycling relates to "spikes" for the sake of the discussion) in events when the filter is killed or damaged and must re-establish as with power outages, poor water quality, or other oxygen/food deprivation> or is it a continual process that happens?  <without spikes on a small scale the bacteria live, reproduce and die in a fast cycle> And are the water changes done just to prevent any danger to the livestock?  <dilution of accumulated nitrate, toxins, dissolved organics, etc> So if there is no livestock in the tank, will leaving it alone simply cause a "cycle" to happen.  <no... without a source of ammonia...little or no biological activity will occur/develop as it relates to "cycling".> To help you better understand, think of a QT where there are times that nothing will be in there - must water changes be done on a ritual basis or will ammonia clear itself using typical "cycling" effects? <good question... such a tank would need to be fed with a source of food/ammonia at times when fish were not present. For this reason it is better more convenient) and not necessary to keep a QT tank running at all times. Simple keep an extra biological filter (sponge type) running on the main display at all times. Then when the need for a QT tank arises...simply move the established/dirty sponge filter over to the QT tank with some aged water and some new water and stock with fish immediately (the sick or new fish that needs QT). The biological filter will continue in stride without spikes most likely> Thank you for clarifying this for me. Debra <best regards, Anthony Calfo>

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