10 Gallon Tank Trouble Acclimating Corys. No Eating


What is the water volume of the tank? 10 gallon
How long has the tank been running? 3 weeks (but with filter media from cycled tank). 1 week with fish
Does it have a filter? Yes
Does it have a heater? Yes
What is the water temperature? 75 F
What is the entire stocking of this tank? (Please list all fish and inverts.) Quarantine tank so just one Julii (probably false) cory. I had bought 2 but one died

How often do you change the water? Been doing every 2 or 3 days in the Quarantine tank
How much of the water do you change? 20%, 2 gallons
What do you use to treat your water? Prime. but I also have Stress Coat and Microbe Lift Artemiss in there
Do you vacuum the substrate or just the water? Have not vacuumed in the Quarantine tank

*Parameters - Very Important
Did you cycle your tank before adding fish? I let filter media sit in a cycled filter for 10 days before putting in the tank.
What do you use to test the water? API test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0.25 ppm (my tap water has about .50 ppm naturally so I use a full dose of Prime every day to deactivate until it goes down)
Nitrite: 0 ppm
Nitrate: 5.0 ppm
pH: 7.0

How often do you feed your fish? HAS NOT BEEN EATING. I have been providing food twice a day but have to remove it after 15 min because she doesn't eat yet????
How much do you feed your fish? I cut up 1 pellet per fish
What brand of food do you feed your fish? Primarily imagitarium Bottom Feeder Pellets but switch out with Aqueon Shrimp Pellets and Hikari Sinking Wafers
Do you feed frozen or freeze-dried foods? No

Illness & Symptoms
How long have you had this fish? 1 week
How long ago did you first notice these symptoms? She has not ate ever. 3 days ago she swam erratically (see below)
In a few words, can you explain the symptoms? No eating. One day she swam erratically to top of water, froze, floated to bottom and laid on side for 30 sec. This happened about 5 times in 1 hr then never again.
Have you started any treatment for the illness? No
Was your fish physically ill or injured upon purchase? No
How has its behavior and appearance changed, if at all? Still has not ate, developed a pale color and red blotch on head the same day she swam funny (3 days after I got her but has been fine for about 3 days)

Explain your emergency situation in detail. (Please give a clear explanation of what is going on, include details from the beginning of the illness leading up to now)

Saturday I bought 2 corys from fish store (both about an inch long). I brought them home and acclimated them to my quarantine tank (float for 15 min. then add a small cup of water every 10 min for 4 times then dump some out and did 2 more times). 5 min after they got into the tank, the smallest fish would swim straight up, freeze except for gilling, then lay still on its side for a little. She did this for about 45 min. Then was fine for 2 days before suddenly dying. The other cory was fine for 3 days before she did this same behavior for less than an hour but has been fine ever since. The now dead cory and the one that I have had for 6 days now did not eat anything yet. The one I have now is still VERY active. She is sifting over the decorations and swimming across the tank. But has not ate; she does not appear to be getting thin though. I added some sand in the corner to try entice her to feed there sifting through the sad. I have a bubbler in the tank.

I am worried that she might die suddenly in a day as well? Is there anything I can do or am doing wrong? My ammonia has 0.25 ppm because my tap water has 0.50 ppm so when I do water changes it actually makes it worse so I dose with Prime and make sure there is "active" Prime in the tank by adding some daily until the filter can remove it. I do not know if her sudden erratic behavior was due to some ammonia affecting her?

I am also confused why the cory that died reacted differently to the acclimation than the one I still have? I contacted the store and they had just got these corys the day before. I read online that this much shipping, new tank, to my tank can be a lot of stress on fish and reduce their survival rate?

I have 2 corys in an established tank since January that I am trying to get a full school for them. But originally I bought 2 corys for them a month ago and was (wrongly) instructed by fish store to put them directly into my tank instead of the quarantine tank I had set up so they would have less adjusting to do. So I put them in with my 2 corys and betta fish to have the new corys die and kill my betta fish with columanris within 24 hrs . I want to get a school but I am getting discouraged. I really want to make sure I am giving them the best chance despite potentially "bad stock" from the store.

I am also looking for advice since I am trying to get 2 more to complete my school and want to do better next time.

The pictures are of her facing right with the red blotch the day she did the erratic swimming. Then yesterday she looks better coloring and red is reduced. Picture for size of the two; the smaller one died even though they both looked "healthy".


Do they have places to hide? And is there sand anywhere in that tank for them to sift through and mine seem to like to eat a little after I add the food so the sand can kind of cover it a bit
  • Thread Starter


AggressiveAquatics said:
Do they have places to hide? And is there sand anywhere in that tank for them to sift through and mine seem to like to eat a little after I add the food so the sand can kind of cover it a bit
Hi! I have 1 live plant that the cory has been running along. And then one fake plant with a hide in the center and one circle cave. I originally did not have sand in the tank because I read that if you need to add a treatment in the tank, sand can mess with the dosage. But since she does not appear to have obvious infection/disease signs, I added a thin layer to a quarter of the tank yesterday. She has been hanging out over it some!


It's hard to say with a red patch like that. It can be a sign of infection, it can be inflammation, it can even be physical damage (rough handling at the pet store or in shipment). I will say that I also recently saw false Juliis specifically in an otherwise good pet store with red patches on the body, so don't know if a supplier or farm that produces those is having an issue.

If ammonia in your tap water is an issue, you could get an adsorbent to soak it up, such as Purigen or Zeolite (you'd want to take them out if medicating a tank, though.)

I haven't run across this myself (in a fish I had myself) to be able to tell you what worked for me or didn't, so the best I can advise is giving the remaining one the best water-quality possible, and see if it gets better. Without knowing for sure what the cause of the red is, it's difficult to advise on treating it, beyond reducing environmental stress.

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