• Get the NEW AquariaCentral iOS app --> http://itunes.apple.com/app/id1227181058 // Android version will be out soon!

HELP!!!Sudden ammonia spike on a tank that has been cycled for years

platytetrafan

AC Members
I have a 36 gallon bow tank I know my fish load has gone way down. I was planning on starting to increase my fish load by setting up my QT this week and slowly add one school at a time and then if healthy after 4 weeks for each school add them slowly to my 36 gallon. Last month I was a little lazy and didn't do my usually 2 week partial wc and let it go another week when I tested the water got a small ammonia spike and had to do 2 back to back wc's but got the ammonia to 0.

I should have more than 7 fish in this tank but some had died over time due to age the water conditions had always been pretty good. I didn't have the time to set up a QT until now. I was feeding lightly or so I thought Wed I checked the tank water and the ammonia level was at 1.0 so I did 2 large back to back water changes and gravel vac with no change the ammonia stayed the same, did one more and it actually went higher. Nitrite was 0 so Thursday I did another partial wc and now today Friday the ammonia level is higher at 4.0 nitrate is 0 ph is 7.6 nitrite is 0. What could be going on? Did I lose my cycle? I dechlorinate the water I use to put back into the tank so is this tank mini cycling? Besides water changes what can I do to decrease the ammonia and why is my nitrate that has always been between 10-20 now at 0? The tank is not planted and is freshwater.

I know I have to increase the schools of fish in this tank but before adding any new fish they have to go through QT anyway. Any ideas to help? I know I went too long between water changes but last month 2 back to back water changes did the trick and now my levels are bonkers. Any advise would be appreciated in the mean time am doing a water change now.FYI I have the original filter in my peguin 200 and a small waterfall filter that I put in there for my QT if I remove that filter am I going to have a huge problem because my larger filter doesn't look like it has any good bacterial stuff on it. I know that there is some in the gravel but with such a light fish load will removing that other fish sponge cause a big problem for me? Need advise big time the things is my fish look ok and are swimming around. I have one cory 4 cherry barbs 1 bleeding heart tetra and 1 rasbora I know pretty pathetic.
 
If ammonia is increasing, there's a cause for that.

Clean out everything possible in your tank and the filter, look for bodies or any large items that are decaying and discard them, slow down on feeding, and treat it like you are cycling again, high ammonia values will kill off your beneficial bacteria.

it's always going to be helpful to record your tests with the date and time, and then the specific reading for each test, also take note if you test before or after a water change.

also think about if anyhting happened with your water supply, if they suddenly used chrloramine for a few days to flush out the system, or if you forgot to condition your water.

by the way, what is your source of water, and how does that read for ammonia and nitrate.. also what are you using to dechlorinate.


my advice right now is to change water more often unless there's a problem from the tap, that should help manage the levels of ammonia and nitrite until it's safe.
 

platytetrafan

AC Members
If ammonia is increasing, there's a cause for that.

Clean out everything possible in your tank and the filter, look for bodies or any large items that are decaying and discard them, slow down on feeding, and treat it like you are cycling again, high ammonia values will kill off your beneficial bacteria.

it's always going to be helpful to record your tests with the date and time, and then the specific reading for each test, also take note if you test before or after a water change.

also think about if anyhting happened with your water supply, if they suddenly used chrloramine for a few days to flush out the system, or if you forgot to condition your water.

by the way, what is your source of water, and how does that read for ammonia and nitrate.. also what are you using to dechlorinate.


my advice right now is to change water more often unless there's a problem from the tap, that should help manage the levels of ammonia and nitrite until it's safe.

I am using a declorinator called Aqueon and tested my tap water after using it it shows 0 ammonia for the water am adding back to the tank. I gravel vac'd this tank this past Wed and did a 75% wc after testing the water and got 1.0 ammonia and also did water changes Thurs and today. My nitrite levels have been 0 but I am showing no nitrate when my levels when I had more than 7 fish in the tank always read between 10-20. I just spoke to my broinlaw who also has fish tanks and he suggested prime but from what I read that is a dechlorinator as well but I need something that has beneficial bacteria in it I remember using it when I first cycled this tank and it has been cycled for a long time. Am thinking this is a mini cycle but I need something that is going to boost my micro load and stop these ammonia spikes I know water changes are necessary. Thanks for your input appreciate it.
 

the loach

AC Members
How are the fish doing?
What kind of test kit are you using? Could readings have been wrong because it aged, it's not very accurate or you didn't test it correctly? 4ppm would have killed your fish.
 
Depending on how the Dechlor works, it may bind Chlorine to ammonium, which will give false readings.

my instinct is honestly to use a dechlorinator like Prime or Oltimate.. I know lots of folks in the hobby without issue, but I've known sudden issues like this because of water companies flushing their systems periodically.

If you can't get beneficial bacteria from someone you trust in the hobby (squeeze their filter cartridge into your tank is the simplest way) I'd normally manage the issue with water changes daily and lowering feeding rather than bacteria in a bottle.

any which way, a good and reliable water test will be your best friend. Getting a second opinion from a fish store might be a good idea too.
 

platytetrafan

AC Members
The fish are doing fine that's what's so crazy I have been doing 50% water changes daily and just tested again and the test drops are showing 0.5 ammonia now. I have been using Aqueon water conditioner and on the bottle it says that it neutralizes chlorine and chloramines in tap water and detoxifies heavy metals and ammonia. When I got the reading of 4.0 earlier last week I couldn't believe it because I agree all the fish would have been dead but what is so strange is that I tested the water that I was putting back into the tank after dechlorinating it with the conditioner and the test drops tested it as 0 ammonia. When I did my 50% wc yesterday I also did one more gravel vac. I am hoping that this last wc brings the levels back to normal. I haven't fed anything to the fish in days didn't want to possibly increase the levels any further. If by tomorrow the level of ammonia is not at 0 I will bring the water to my LFS have them test it and then decide what else to do. Very frustrated!!! Thanks for all the replies and advise I do appreciate it! :)
 

platytetrafan

AC Members
How are the fish doing?
What kind of test kit are you using? Could readings have been wrong because it aged, it's not very accurate or you didn't test it correctly? 4ppm would have killed your fish.
I only use API drops for testing not test strips. I bought 2 new bottles of ammonia and nitrate drops as I will need them anyway once I set up my QT tank.
 
Last edited:

platytetrafan

AC Members
Still ammonia at 0.5 doing a Wc will see what happens after another 50% wc if later this morning tank water is still showing signs of ammonia bringing a sample to LFS have them test it and see if they have Prime. Smh this is crazy fish are doing ok
 

the loach

AC Members
I'm glad to hear the fish are fine ! Is the tank planted ?
Still I doubt that there is ammonia in there. 6 small fish in a 36 gallon don't just cause a huge ammonia spike, and you don't kill nitrifying bacteria by not doing water changes for a month. Have you used medications prior to that which kill bacteria?
 
zoomed.com
hikariusa.com
aqaimports.com
Store
Top