New tank, no fish, high Nitrite

Henlil

New Fish
Sep 7, 2010
5
0
0
Bristol, UK
#1
We have had a new 48L tank running, with no fish in it for three weeks and have high nitrite levels. I have done 20%, 50% and completely changed the water, as advised, without any variation in the nitrite level. I have tested the tap water we are putting in , which is fine. We have tried filter start and cycle treatments but again it makes no difference. We have never had a fish tank before and are completely stuck as what to try next. Please help!!
 

achase

Large Fish
Feb 1, 2010
765
0
0
British Columbia, Canada
#2
Welcome to the forum and to the world of fish keeping!!

By cycle treatments what do you mean? Your tank will need to be cycled before you should add fish, this can take a bit (like a month) and during this time ammonia, nitrite and nitrate levels will fluctuate. Do you have liquid test kit that can also test for ammonia and nitrate?

Here is an article on cycling: fishless cycle
 

Henlil

New Fish
Sep 7, 2010
5
0
0
Bristol, UK
#3
Sorry Cycle is a brand name it is a biological aquarium suppliment which eliminates nitrites and ammonia. we have tested for ammonia which is zero. I have a test kit for everything.
In the tank we have: -
washed gravel
2 live plants
a sunken ship!!!
 

jamiejay09

Large Fish
Dec 14, 2009
421
0
0
England
#4
welcome to the forum,

Your tank needs to be cycled correctly as said by achase, Now you need to use a water conditioner on your tap water no matter what readings you get from the test you have done on it.
 

prsturm

Large Fish
Aug 13, 2010
100
0
0
#6
Well, it takes about a week or so after your ammonia is being eaten to establish the bacteria that feed on NO2. Mine took about 5 days. If there are no fish in the tank, let the tank sit for 3 days without a water change. You'll finally start to see your nitrite come down to readable levels. A few more days and it should be good to go.
 

misterking

Superstar Fish
Aug 12, 2008
1,124
0
0
Manchester, UK
www.facebook.com
#7
Just a quick note - the cycle stuff you're using is a waste of money unless it was refrigerated at the store. It's effectively bacteria in a bottle which dies without any source of nutrients etc.

I'm glad you're testing for ammonia, nitrite and nitrate, so many new-comers on here don't. The others are quite right in what they're saying about cycling the tank properly and you're already on the way.
 

Feb 27, 2009
4,395
0
36
#8
Well, it takes about a week or so after your ammonia is being eaten to establish the bacteria that feed on NO2. Mine took about 5 days. If there are no fish in the tank, let the tank sit for 3 days without a water change. You'll finally start to see your nitrite come down to readable levels. A few more days and it should be good to go.
How would letting your tank sit for 8 days+ make it 'good to go' and safe for fish?
 

prsturm

Large Fish
Aug 13, 2010
100
0
0
#9
How would letting your tank sit for 8 days+ make it 'good to go' and safe for fish?
It gives the bacteria some time to establish itself before you keep de-nitrifying their food source with every-day water changes w/ chemicals, with no fish in the tank. It is very easy to stall the cycle at the NO2->NO3 stage. This is assuming he's cycled through the ammonia, but stalled at the nitrites.
 

Feb 27, 2009
4,395
0
36
#10
It gives the bacteria some time to establish itself before you keep de-nitrifying their food source with every-day water changes w/ chemicals, with no fish in the tank. It is very easy to stall the cycle at the NO2->NO3 stage. This is assuming he's cycled through the ammonia, but stalled at the nitrites.
With no fish in the tank, what is the food source? The 'chemicals'?
 

prsturm

Large Fish
Aug 13, 2010
100
0
0
#13
You missed my qualifier: "assuming he has already cycled through the ammonia". I figured he was seeding his tank for three weeks since he said its been three weeks and kept it empty. I could be wrong, but I don't think he just kept an empty tank for three weeks without doing anything to it.
 

achase

Large Fish
Feb 1, 2010
765
0
0
British Columbia, Canada
#14
I think it has been sitting empty and they have been using products that say they cycle the tank instantly (bacteria in a bottle). So we will have to wait for a reply.

I don't think he just kept an empty tank for three weeks without doing anything to it.
I have known newbie's to do this who thought they were cycling it. Not necessarily this individual but it has been known to happen.

Once you stop adding ammonia to the tank when your cycle is complete its a good idea to let it rest for 24hrs or more to give the bacteria a chance to eat the ammonia and not expose your fish to ammonia.
 

Aug 16, 2009
1,318
0
0
SW Pennsylvania
#15
Many, many new fish keepers let their tank sit for weeks, thinking it will cycle without an ammonia source. The pamphlet that comes with most fish tanks gives bogus advice and tells the new and inexperienced fish keeper to let the tank sit for a day or two before adding fish. I believed this as a newbie and while it may seem like a silly thing to do, people are easily beguiled if they do not do proper research.
 

Henlil

New Fish
Sep 7, 2010
5
0
0
Bristol, UK
#16
How much ammonia do I add (48L tank)

I think it has been sitting empty and they have been using products that say they cycle the tank instantly (bacteria in a bottle). So we will have to wait for a reply.

I have known newbie's to do this who thought they were cycling it. Not necessarily this individual but it has been known to happen.

Once you stop adding ammonia to the tank when your cycle is complete its a good idea to let it rest for 24hrs or more to give the bacteria a chance to eat the ammonia and not expose your fish to ammonia.

I have never been told/instructed to add ammonia by anybody in an aquatic store, which I find strange, in which case how much and how often should I add it?
 

achase

Large Fish
Feb 1, 2010
765
0
0
British Columbia, Canada
#17
Ammonia is used in a fishless cycle to establish good bacteria. Fish produce waste which equals ammonia and the bacteria eats the ammonia making the tank safe for your fish. So when you cycle without fish in the tank you need a source of food for the bacteria.

Staff at aquatic stores can be very misleading sometimes because they don't know better or because they are trying to make a sale. It's always better to do your own research and coming to this forum was a good place to seek advice.

Here are two articles on the fishless cycle: fishless and fishless cycle (which is the one I used to cycle my tanks)
 

brian1973

Superstar Fish
Jan 20, 2008
2,001
3
38
Corpus Christi, Texas
#19
hey I have a quick question, I read this thread completely. I have been doing this for a while but havent done a cycle in years so maybe i forgot the basics but I dont think so, so correct me if I am wrong. During the cycle process ammonia is introduced via fish, ammonia, whatever, this is converted to NITRITES, this is then converted to NITRATE once your ammonia and nitrite level is zero and you have some nitrate reading your cycle is complete. So based on this understanding, how does the OP have any NITRITE reading without having ammonia, they have no nitrite out of the tap so something has be creating this, the cycle product maybe?? therefore it is reasonable he/she is stuck at the nitrite process and just needs to stop doing water changes and wait for the nitrite to drop and the nitrate to begin registering or to stop any chance of error, drain the tank, stop adding chemicals other than dechlorinator, and add ammonia and begin the cycle process from scratch.

Just a side note the bacteria supplements for freshwater tanks are now sold on the shelf and are advertised as no refrigeration needed, Tetra safestart used to be marketed as marineland freshwater bio spira ( SAFESTART (instant tank cycler)(replacement for MarineLand "bio-spira"))
 

Last edited:
Feb 27, 2009
4,395
0
36
#20
What other ammonia sources could be used besides pure ammonia? I mean, I've heard some people suggest a dead shrimp, for example . . . .
Adding pure ammonia is the best way to keep the levels stable, but anything that decays will produce ammonia: dead fish, dead shrimp, dead plants, fish food, etc. Anything organic (was once alive) will produce ammonia when the bacteria breaks it down during the decay process.