# What is this large spot on my new black neon?



## Jenniferinfl (May 3, 2013)

The spot is on both sides of the spine and almost identical on each side. 

There was no discoloration this morning before I left for work at 4 AM. When I came home at 11 AM there was this huge spot on both sides. They were all hanging out around the heater, is there any chance this is a burn? It just seems to have come on very quickly in a very short amount of time. 

Edited to add:
Tank size: 40 gallon breeder
Ammonia: 0 ppm
NitrIte: 0 ppm
NitrAte: 20 ppm just before water change
PH/GH/KH: 7.5
Cycled,yes or no: yes
Number of fish: 11 adult fish (tetras), some sailfin fry
Acclimation process: Bag floated for half an hour, netted out of bag and added to tank as fish store is on same municipal water source and doesn't adjust pH. 
Physical signs of illness(IE spots,shimmer,ECT): Large spot on one fish that appeared over the course of 6 hours or so.
How often between fish additions: 1 remaining adult and fry from about 13 days ago, other ten fish added yesterday
Waterchange schedule: 10% every other day, will up to 25% as needed, I test the water everyday
Tank temp: 83


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## coralbandit (Jul 29, 2012)

Tough call,but I'll run with columnaris.
I would lower your temp a little slowly.78 should be max for most fish.
Keep up on w/c and testing as you just dropped a large load on your tank all at once.


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## Jenniferinfl (May 3, 2013)

Well, strangely enough the fish died while I was out at the store picking up some Maracyn II I'd found recommended elsewhere. Additionally, and this is the odd part, the spot was gone once the fish was dead. The whole body is very uniform and I've just stared at the remaining 4 of them for half an hour this evening convincing myself that none of them have so much as a dot out of the ordinary on them. 

Hmm, thus begins a waiting game to see what happens now. 

I've been testing ammonia twice a day and everything else just once a day, is that adequate or should I be testing more often? So far ammonia is being kind to me and holding at 0. I had overfed the tank during the last week when it was just the fry and one adult remaining. But, I was also doing 10-25% water changes everyday in hopes of keeping the good bacteria cranking away but not dirtying the water too much. Either way plan to change at least 10% daily as these tetras seem to be rather fussy. I'm beginning to wonder if perhaps I shouldn't just spring for a RO system to eliminate the possibility that there is something in my municipal water that they don't like. The water is treated with prime and I only add it to the tank once it is within a couple tenths of a degree. Oh well, another head scratcher, but, guess we'll see what tomorrow brings.


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## Jenniferinfl (May 3, 2013)

To update I had one more die overnight and brought both back to the store. This time the aquarium area manager was there instead of a fill in cashier. It turns out they got their shipment in a day earlier than usual, so when I bought them they had just been let out of shipping bags. 

So, I replaced the two that died with two lively looking ones. I still have one in the tank from the original 5 that doesn't seem to be adjusting that well, just hanging out in the plants, but all the others are schooling around. So, I'm guessing it was just something to do with shipping stress.

The group of 5 pristella tetras I got are just lively as can be and have already made themselves at home. 

Ammonia still at 0 both times I tested today, so far looks like I had a good bacterial load built up. I'm going to keep up with 10% water changes daily anyways for awhile and then maybe go to 25% every 3 days after that. 

It's still weird whatever that huge spot was, especially that it disappeared after the fish died.


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## rtmaston (Jul 14, 2012)

next time you go to your lfs I would carry a water sample and see if thay match what you got.hope the rest of your fish do fine.


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## Jenniferinfl (May 3, 2013)

Unfortunately the closest LFS is a 45 minute drive away and really only carries African cichlids. 

The Petco near me requires a water sample for return because they don't cover losses if your parameters are off. 

They got a 0 on ammonia and I didn't notice the other thing they tested, but they said both were fine. I'm assuming they would have tested for nitrates, but, I'm not sure. 

But, they take the lazy way out and use strips, at least I'm using the API master kit. I did take two semesters of college chemistry, so I'm confident I'm performing the tests correctly. Is that kit known to be flawed? I know you can get unusual results with the strips which is why I opted for the liquid kit. Hopefully that isn't know for large errors as well.


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## coralbandit (Jul 29, 2012)

Api liquid test are pretty accurate.Most here use them and none seem to complain.I use API for my reef test kit also and have had no problems.Probly just a bad batch of fish.


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