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rsskylight04 11-10-2013 11:13 PM

nitrogen cycle water quality
Who knows about the bacteria that cycle ammonia and nitrates in aquarium water. How can I encourage the best possible environment for good bacteria growth. Any info is well appreciated

Romad 11-11-2013 07:51 AM

Have you read these sticky threads on the nitrogen cycle and bacteria in the freshwater tank? This will be a good start.

beaslbob 11-11-2013 08:20 AM


Originally Posted by rsskylight04 (Post 3378569)
Who knows about the bacteria that cycle ammonia and nitrates in aquarium water. How can I encourage the best possible environment for good bacteria growth. Any info is well appreciated

You add fast growing live plants.

my .02

Flear 11-11-2013 10:50 PM

ammonia is produced by a ton of different methods of non-photosynthetic oxigen rich environment
how ammonia is produced isn't a concern, we know it's going to be produced in massive enough quantities we are very thankful for other bacterial processes that break it down.

it's not simple,

once ammonia is produced, it depends on your ph what happens first
if the ph is low, then you get ammonium, (under 6.5 is almost all ammonium)
ammonium is safe, very safe
above 6.5 you start having small amounts of ammonia (this is the toxic one)
at about 9.5 it's about 50/50

i don't know squat about ammonium being converted
i know plants can use ammonium directly, ... plants are good

i don't know the names of the types of bacteria either, only the processes involved in the nitrogen cycle, the simplified nitrogen cycle

the first one converts ammonia to nitrites, ... i've as toxic as ammonia, i've also heard more toxic, ... i dono
next, ... roll the dice, we hope the next one will convert to nitrates
a bad roll could convert to ammonia again, ... is this likely no, but lets follow the simple cycle and leave it at that

nitrates are still toxic, but safer than what the tank has gone through
plants can use nitrates easily.

i have heard (and forgotten about light levels that help or limit one of these bacteria (converting to nitritres or nitrates), i think it needs dark, ... so pick an opaque substrate (an idea i had for a time was sand blasting glass beads, perfectly round for sensitive skins of some fish), but if it inhibits or limits the nitrogen cycle into nitrates, it's not worth it in my mind.

if you've got sufficient plants then you don't have to do water changes due to nitrates (possibly for other reasons, but not for nitrates)

if you don't have plants, you have 2 choices
change water, or ...
pick live rock (give it time to culture) and another bacteria steps into the picture

converts nitrates into harmless nitrogen gas, ... this is only done in anoxic environments (if i have the right word), ... without oxigen environments, ... deep inside the live rock, osmosis will bring in nitrates, and move out nitrogen gas.

could also bring about the same process with a deep sand bed (5" or more of substrate)
don't listen to the fears about the Deep sand bed if you have plants, don't clean a deep sand bed
don't disturb your DSB, just leave it alone, ... it will accumulate a ton of nutrients till you are wondering (after a few years) why you have mud in the bottom of the tank
oh ya, and if you have plants the roots will bring oxigen into the substrate, and defeat the process of converting nitrates into nitrogen gas.

but if you have plants the plants will reduce the nitrates and once more things are healthy

for marine tanks, coral rock is what's used, ... just left alone it cultures and all is good
for freshwater if you want your PH low, don't use this as the calcium will bring your PH to 8 or more
porous lava rock is a good alternative

regardless of the live rock options, i am sure the measures are the same, X pounds of life rock per gallon of water, i don't remember, have a look in marine/coral sections to find out


long story short, don't care about any of the above, so long as your ammonia and nitrites are near zero it's good, for new tanks this is expected to take 4-6 weeks.
if you have plants you can have nitrates up to 40

if you have live rock & plants, you might have nitrogen deficiencies in your plants
if you have a DSB and plants, your plants are going to be undoing the anoxic layer and no denitrification is going to be happening

once things are reduced to nitrates, pick one means of handling it, and/or you can combine with water changes


a more complicated nitrogen cycle
add ammonium into the mix
and there are bacteria that can convert various nitrogen molecules into all kinds of other different nitrogen molecules, ... some of these are toxic to have in tanks, some go against the nitrogen cycle. ... the simplified nitrogen cycle wins out as nitrogen compounds that are produced in abundance will also promote bacteria that process the compounds into the regular simplified nitrogen cycle till things balance out in a stable cycle

cyano bacteria can also play a part in the nitrogen cycle
from what i've seen of cyano it's limited/controlled with oxigenated water flow, ... still water down at the substrate can be a bad breeding ground for cyano, once started it's much harder to remove then never having it to begin with, ... so far cyanobacteria is the only source i've heard of that we have commonly available to our aquariums that can directly make use of dissolved N2 gas in the water, i don't remember where it converts it to on the nitrogen cycle of our aquariums., ... overall not a good thing to have in our tanks though, ... there are cyano strains that are safe, but others are toxic and nothing will eat it.

rsskylight04 11-11-2013 11:20 PM

Thanks for your very detailed answer. Do you know, where is the main population of good bacteria? Is it the filter... or the substrate... or the water itself? Also is it ok to move substrate from my established tank to a new tank? Will it help cycle the tank or is it just a waste of my valuable bacteria? Does it help to move slimy rocks frommy old tank to the new one? Thanks for the knowledge, you guys are great!

Flear 11-11-2013 11:32 PM


Originally Posted by rsskylight04 (Post 3378569)
Who knows about the bacteria that cycle ammonia and nitrates in aquarium water. How can I encourage the best possible environment for good bacteria growth. Any info is well appreciated

"best", ... sorry about this, ... i will never think of someone who wants "best" as a person who knows anything about what they're asking

there is no such thing as "best"
best for what ?
best for plants
best for completing the nitrogen cycle
best for what ?

as for best for the nitrogen cycle itself, ... i've never looked into that
what kind of substrate, particle size, light, temperature, PH, oxigen, ... and other.

if you're only worried about the nitrogen cycle, don't
think about what you want to get out of it, think about what you want in the tank that you are concerned about the nitrogen cycle for, but just the nitrogen cycle, ... like worrying about if your tires are 30psi or 40 psi when your already late for an interview

what do you have in your tank ?
do you have plants ?
do you have other critters ?
water changes ?
light ?
PH ?
nutrients ?
new or established tank ?

even then all these questions boil down to:
new or established tank ?
plants or not ?

and notice none of these questions are about feeding (overfeeding can increase ammonia, then through bacterial conversions result in nitrates) unless it's extreme

from personal experience:
do you have snails ?
if your fish are small enough (or your snails large enough) they will eat dead fish and you will never experience an ammonia spike, ... larger fish not so much (unless your snail population is beyond extreme)

do you have any creatures that deal with dead/dying things in the tank (most people don't)

do you need to worry about the nitrogen cycle ?

unless your building a tank your throwing dead things into
on the net somewhere (another forum) a lady has a tank with a DSB, she describes going as far as burying the dead fish and critters to provide nutrients under the substrate for plants, ... never an ammonia spike, ... so there's a lot of leniency in things, a lot of room to not care till you get so far into extreme, and even then, there's ways to handle it.

Flear 11-11-2013 11:38 PM

where the majority of the bacteria is ?
wherever the majority of the surface area is

if you've got gravel & a bunch of sponges in your filter, then your filter has the majority of the bacteria
if you've got sand then regardless of the filter, that's the majority of your bacteria
if you've got a bare bottom tank (actually a serious way some set there tanks up who have coral) then the surfaces inside the tank (including everything else in the tank)

if that's your question "where is the bacteria"
just look for a substrate with lots of surface area, use sand instead of gravel
personally i'd stick with 2" or less if you don't have plants and don't clean your substrate on a regular basis.

if you have plants, as deep a substrate as you want
if you have coral, might be better without a substrate at all, go bare bottom
it's more important to know what is in your tank instead, then worry about the substrate later, or where your bacteria is going to culture that keeps the nitrogen cycle healthy
if your replacing your filters on a regular basis, then don't count it

rsskylight04 11-11-2013 11:46 PM

I have a very well established 75 gall with 1 jack dempsey and 2 pictus cats. My reason for asking is that this tank has been up and running for 6 years with never a problem. I want to really understand what is going so good in there so that I might reproduce the resultts in other tanks... instead of crossing my fingers and hoping for the best. Sounds like plants are very good for the water, but I can't have any... the dempsey shreds them just for fun! Based on your posts and the excellent reference materials written by byron, I guess the deep gravel bed that I have in my tank has helped to keep it so stable. Water is crystal clear and fish are very healthy. Flear is right that there is no one best way to maintain a tank, my focus is on optimal waterquality fot my fish. Thanks for the intelligence!

Flear 11-11-2013 11:53 PM

java fern & anubias are very resistant plants, ... just look for plants safe for a goldfish tank

Hallyx 11-26-2013 02:52 PM

Flear takes the nitrogen cycle too casually for my taste. A strong cycle keeps nitrous toxins at 0.0ppm, done right. An unstable cycle can crash creating dangerous ammonia spikes. A large or rapidly-increased bioload can be easily overload too small a bacteria colony, leading to ammonia spikes.

I started my research into the nitrogen cycle here: Aquarium Nitrogen Cycle | Cycling Methods | Ammonia & Nitrates

Strohmeyer is an old-school professional aquarist. While there may be a few ways to promote a cycle, his are good fundamentals. This article will specify which bacteria do which job in what order.

Research and experiment have shown me that lots of O2 and a temperature around 84* F encourage the cycle, along with hard water and high pH, and darkness. I suppose you already know that soft water and low pH (below 6.5) will discourage the cycle.

Heavy planting removes ammonia before the bacteria can get to it. So a planted tank has a smaller bacteria colony; but, then, a larger one is not necessary. Some people call this a "silent cycle." I find the term inaccurate and misleading.

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