Nitrite Spike, Water Change, Fish Now At Deaths Door.

[JenniferRose]

While doing my daily tank test run (We have three tanks, all 2.5 gallons with filters) I found that one of the tanks is running REALLY high on nitrates. I did an emergency water change of 1/3 of the water, tested again to see little to no difference. We run on well water so I had to filter and allow the water to sit before using it, thus couldn't do another change right away. I looked at him tonight and he was gasping for air, floating sideways up on the top. Poor little guy is on deaths door.  Testing the water again the nitrates had spiked even higher, nearly off the charts. I know ammonia is converted into Nitrates, and then a separate bacteria converts nitrates into nitrites. I can tell this tank is trying to cycle still. I do 1/4 water changes 2 times a week unless ammonia levels dictate a water change is needed sooner. 
 
As a last ditch effort to save him (nitrates that high I figured were an auto death sentence) I moved him into a small container of water that I'd treated and had sitting for a couple hours. Temps were exactly the same between both containers of water. I'm pretty sure I'm going to wake up to a dead fish.   At least the water was more comfortable for him (I'd hope?) I know you aren't supposed to do this normally but seeing as the nitrates were off the charts, I figured it was better than leaving him in there. 
 
This tank was NOT cycled properly before getting the fish, the tank has been running about a month. It's my parent's fish, and they bought him against my suggestions on an impulse buy. (ugh). The tank is 2.5 gallons which I've read is nearly impossible to properly cycle. Which leads to my main question... 
 
If this fish doesn't survive I know my mother will insist on getting another betta. Do we have to sanitize everything and start over or can we take advantage of the bacteria we DO have and use this tank, maybe with fresh water but old gravel/filter? He was acting perfectly healthy a couple days ago, and the water parameters were showing in normal range. I do not want this to happen to another betta and will refuse to let my mother buy another fish on impulse! 

Everything I've read about cycling is for 10+ gallon tanks, so any reliable links to small tank cycling would be appreciated. 
 

 

[JenniferRose]

amazingly this morning he is still kicking!   I'm guessing his gills were burned due to the spike in nitrates? He's still right at the top, gasping for air. He swims really strangly, flailing when he's aggitated. Should I keep him in a small container for now until he recovers? I'd have to keep an extremely close eye on water quality but I always have water at the ready to change a tank. (And am doubling up on the back up water supply now..) 
 
I have him in a small (pint sized) container with a betta leaf for him to lay on. 

Oh, how long would his gills take to recover? 

 

[Essjay]

I assume you really mean the tank's nitrite is high as the nitrogen cycle is ammonia -> nitrite -> nitrate.
 
The water in the small container will quickly build up ammonia if there is no mature media in there. He is better off in the 2.5 gall tank with its larger water volume. But before moving him back, do a 100% water change on the tank so there is no ammonia or nitrite. Then monitor the levels every day and do a water change as often as necessary to keep nitrite from getting any higher than 0.25.
This does mean making sure you always have enough water prepared to do a 100% water change should this prove necessary.
 
It is no more difficult cycling small tanks like this. It is simply that ammonia and/or nitrite build up faster than larger tanks with their bigger amount of water to dilute the toxins.
 
 
 
Should this betta succumb to the high nitrite level, I would just do a 100% water change to get ammonia and nitrite to zero, then get some ammonia and continue doing a fishless cycle as per the method on here. Once that is complete you can let your mother buy another fish. You don't need to sanitise anything unless the fish dies of some very infectious disease, and even then running the tank with no fish while it cycles would probably get rid of any pathogens.

 

[ShinySideUp]

Nitrates are not good but not that bad either. Nitrites are almost as toxic as ammonia. Unless there is something very wrong with your fresh water supply it would be better than water with a high nitrite level.
 
Changing a third of the water when you have a high value of nittrite or ammonia is not enough. For example, if your nitrite is 3 parts per million and you change a third of your water you still have water that contains 2 parts per million -- still toxic to fish -- so you have to change a lot more water than that, perhaps 90+ percent; often and until the filter has had time to catch up and deal with the nasties. It's a balancing act once you have started what is effectively a fish-in cycle.

 

[NickAu]

In cases like this using Seachem Prime also helps.

 

[JenniferRose]

I do use prime, always.

I'm sorry, I meant nitrites. They were of the charts and at completely toxic levels.

The fish passed away this morning, with gills flared. Poor baby. I am insisting my mother cycle the tank before getting another fish, she's not happy with me but oh well. I don't want to torture another fish.

For a 2.5 gallon tank, can it be properly cycled? I did a complete clean out but left the filter. She was using marbles instead of gravel, so I've switched her to gravel. I have a feeling it does much better at holding a bacteria bed? We have 1 other tank that was started at the same time, and has never had an ammonia or nitrite spike, it uses gravel.

Any links is to proper info on cycling a small tank? I've seen many conflicting methods, including seeing that is not possible.

 

[Essjay]

I'm sorry to hear about the betta.
 
Cycling a small tank is exactly the same as cycling a big tank. The method for fishless cycling is here http/www.fishforums.net/index.php?/topic/421488-cycling-your-new-fresh-water-tank-read-this-first/ . Since the tank is already partially cycled, the first part (growing the ammonia eating bacteria) should go very quickly, you (or your mother) will just need to wait for the second part (growing the nitrite eaters) to complete.
You will have lost some bacteria on everything you cleaned and of course there will be none on the new gravel but if you haven't touched the filter there should be bacteria in there.
 
Putting live plants in the tank will also help. You can use floating plants or those like java fern and anubias which are fixed to decor if your mother doesn't want plants in the gravel.
 
 
 
I think the only reason that some people say small tanks are harder to cycle is because when doing a cycle with fish the toxins build up faster - there is a tendency to put more fish-per-gallon in a 2.5 gallon tank than in, say, a 25 gallon tank. The more fish per gall, the more waste that is produced per gall and there is a smaller water:fish ratio to dilute them. With a fishless cycle, it takes the same time as you are adding the ammonia to give the same concentration regardless of the volume.
 
It is always possible to cycle a tank., though really tiny ones (eg those 4 inch cubes you see sold for bettas) might have problems as there is no space for a filter or live plants.