ammonia spike

[phillippa42]

Did a check on water levels last week and everything was fine.

I normally clean my filter every 6 weeks, but on Thursday noticed filter didn't seem to be working very effectively - lack of bubbles. So I checked it and was chocked up so I cleaned it - in tank water. I never use tap water!!!

Then yesterday I noticed one of my cory's is acting funny. Didn't come and feed at dinner time and spends a lot of time at the surface "gasping for air" - but then will go down on the bottom for a bit. On closer inspection his gills looked a bit red. All other fish are fine.

Checked water chemistry, nitrite is 0, nitrate is 5, ammonia is 0.5 , ammonia has always been 0 previously.

I have a 125litre tank.

4 zebra danios, 1 bristle nose, 3 yo-yp loaches and 1 molly and 5 sterbai corys, so I'm not overstocked.

Why did the ammonia spike happen? Is it due to the filter getting a bit clogged b4 I noticed )

I did a 10% water change last night, another this morning and I'm going to do another at midday and one this afternoon. Keeping an eye on ammonia levels all the time. Also going to buy an airstone this afternoon to help bump up o2 levels.

Is this OK, will the cory be ok or is it terminal?

thanks

 

[rdd1952]

I would imagine that cleaning the filter caused a mini cycle. If you only rinsed it, it shouldn't have had an affect but if you scrubbed it, you removed the good bacteria. As for the cory, is he having problems swimming? Does he have trouble staying on the bottom? Those are both signs of swim bladder or constipation. If that is the case, a cooked shelled pea may solve the problem. Since you said he had some red around the gills, I don't know if that is the problem or not.

 

[phillippa42]

He seems to be swimming ok. I didn't realise that you shouldn't scrub your filter - I thought as long as you kept it in tank water it was ok - oops.

 

[rdd1952]

Using tank water is just so you aren't putting the filter in chlorinated water and killing the bacteria that way. Using the old tank water ensures that you won't kill the bacteria with chlorine I would step up the size of the water changes until your ammonia and nitrite (you don't have any now but if this is a mini cycle, you will have before it is over) go back to zero. Do 25 to 30 percent changes. Just make sure the water you put back is close to the same temp as what you take out. You said you normally cleaned the filter every 6 weeks so I assume the tank has been running a while. I'm sure you know this already but just in case, make sure you use a dechlorinator when you do the water changes.