Green Cory Turning Greener and White Spots on Tetra

Tank
What is the water volume of the tank?
29G tank. (I’d guess actual water volume is about 28G after substrate and plants/decor.)
How long has the tank been running?
6+months
Does it have a filter?
Yes. HOB Tetra Whisper 30.
Does it have a heater?
Yes
What is the water temperature?
78°
What is the entire stocking of this tank? (Please list all fish and inverts.)
8 Long Fin GloFish Tetra (one is reg white skirt, which is same species)
9 Glofish/Albino Corydoras

Maintenance
How often do you change the water?
Weekly
How much of the water do you change? Usually about 25-30
What do you use to treat your water?
Seachem Prime and Stability
Do you vacuum the substrate or just the water? Both

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water?
API Master Kit and Test Strips in between
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 15
pH: 7.2

Feeding
How often do you feed your fish? 2x daily
How much do you feed your fish?
Depends on what I’m feeding, but usually a pinch of flakes for tetras and 2 sinking wafers for corys. I alternate between that and micro pellets, and I occasionally feed frozen shrimp.
What brand of food do you feed your fish?
GloFish Flakes, Hikari Micro Pellets and Wafer, San Francisco Bay Frozen Shrimp
Do you feed frozen? Occasionally
Do you feed freeze-dried foods? Not usually. I’ve tried, but the tetras don’t seem to care for it.

Illness & Symptoms
How long have you had this fish?
Approx 4 mos
How long ago did you first notice these symptoms? 3 days ago
In a few words, can you explain the symptoms? 2 different fish with different issues: 1.) Green GloFish Cory flashing and turning darker green. 2.) White Skirt Tetra with white spots.
Have you started any treatment for the illness? Not yet, because I’m not sure if it’s fungal or parasitic. Also scared to do a lot of meds or salt bc of corys. I vac’d and did 50% WC 2 days ago.
Was your fish physically ill or injured upon purchase? Not that I noticed.
How has its behavior and appearance changed, if at all? I’ve noticed some aggression and flashing with some of the tetras. Also some hiding, but not sure if that is related to disease or bc of aggression in the tank.

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)

Sorry for the long explanation, but I have two sick fish with different symptoms.

I usually stay on top of the maintenance in my tank, vac and change water weekly. However, my kids and I were very sick recently, and I went 2 weeks without a WC. I also wasn’t as meticulous about checking everything as I usually am. Water had started to turn a slight greenish color, though params were still within range. I ended up losing one tetra and one cory.

The cory was a green GloFish cory (same species as bronze/albino - Corydoras Aeneus). I noticed some odd behavior in him before he died, but the crazier thing I noticed was his coloring. The best way I can describe it is he started to turn a deeper green. My other green corys have a lighter colored head than the rest of their body. He started to turn a deeper color of green all over, including his head (see attached pic). After the cory died, I did a 50% WC and vac. I treated the water with Prime and Stability. I cleaned filter sponges, matrix rocks, floss, etc. in dirty fish water (tried to not go overboard though since I vac’d too) and added a filter cartridge with charcoal. I was hoping if there was any disease in the tank, the WC and AC would help clear it out.

Three days ago, I started to notice some odd behavior in one of my other green corys and more than usual aggression in the tetras. I’ve noticed that one of the green corys has been more active than he was before. He does more glass-surfing, and he has been doing some occasional flashing and heavy breathing. What scares me most is, he seems to be turning a little deeper green like the other cory did before it died. I have no idea what could have caused the issues with my corys other than missing a week of vacuuming the bottom? This Cory didn’t seem to get sick until after the water change though, so I’m wondering if I disturbed the substrate too much and released some gasses possibly?? Or could the increased activity be his way of “scratching an itch”? Edited to add: Otherwise, the cory seems to be ok. He is eating and scavenging normally.

On a separate (but possibly related) note, my white skirt tetra has some white spots on it. Idk how long they have been there exactly, because it is kind of hard to see white spots on a white tetra. I didn’t notice until I saw a spot on its tail. I started inspecting it and noticed more spots on its body that are hard to see without looking very closely in the right lighting. I have included pics, and I think you can see the spots. I think my purple and red tetras now have a couple of spots on them. My first thought was ich, but it’s seems like the spots are too big to be ich? Unless this is how the cysts look before they rupture? I’ve never dealt with ich before, but I have seen it in a pet store aquarium, and it didn’t look like this. It could have been further along though. Could it be some sort of fungus? Either way, I’m concerned about treatment due to sensitivity of my corys to meds and salt. Should I quarantine the tetras or treat the whole tank since it seems one of the corys is sick too? Any advice???

Thanks in advance for reading my long post and trying to help!

Pictures:
1.) First sick cory that died not too long after turning this color.
2.) Second sick cory BEFORE it starting turning “greener”.
3.) Second sick cory after starting to turn “greener”.
4.) Under Blue LED. You can see how the other corys’ heads don’t have as much color compared to sick cory.
5.) White Skirt Tetra with white spots
6.) Red Tetra
7.) Purple Tetra

 

You’ll quickly learn that there are some very vocal glo-fish haters in this forum! Hopefully you are not chased away by silly rhetoric like ‘glo-diseases’, and can ignore those people.

You noted that the white skirt tetra has white spots. That is a good place to start. The corys seem to have slightly clamped fins, but that could be just the photo angles. As you noted, they are simply aeneus corys, so I would do some searches on common issues. Browsing the cory and tetra disease section should help. You might find that both fish have the same issue.

If it is just one tetra and one cory I wouldn’t treat the whole tank just yet either. Hard to tell from one photo, but there seems to be tiny dots on the red one too. Agreed on the no salt for the corys and I think that the charcoal can remove some of the treatments that you are adding, so I might omit that. Good luck!

 

You’ll quickly learn that there are some very vocal glo-fish haters in this forum! Hopefully you are not chased away by silly rhetoric like ‘glo-diseases’, and can ignore those people.

You noted that the white skirt tetra has white spots. That is a good place to start. The corys seem to have slightly clamped fins, but that could be just the photo angles. As you noted, they are simply aeneus corys, so I would do some searches on common issues. Browsing the cory and tetra disease section should help. You might find that both fish have the same issue.

If it is just one tetra and one cory I wouldn’t treat the whole tank just yet either. Hard to tell from one photo, but there seems to be tiny dots on the red one too. Agreed on the no salt for the corys and I think that the charcoal can remove some of the treatments that you are adding, so I might omit that. Good luck!

Thanks for responding and for your encouragement and trying to help. I realize some people aren’t big on Glofish. I don’t like fish that are painted or injected with dyes, but these are not. They are simply brighter colored variations of the natural species. I have two toddlers who absolutely adore them though. They are learning a lot by watching them and learning to love aquatic life, so I really don’t care what the naysayers think.

I have scoured the internet for answers, both here on fishlore and every other site I can find. I can’t find anything about the color in the Glofish corys deepening in response to sickness/stress. I thought I would ask if anyone else has had a similar issue with one, or possibly with an albino/bronze.

My next thought is to treat for whatever the tetras have going on, and maybe it will improve the health of the corys as well. If I didn’t have the corys, I’d probably treat for Ich and see if there were any improvements in the tetras. However, the corys make me nervous about increasing the temp or adding salt/meds. I’d like to be sure I’m at least treating for the right illness. I know I need to take the AC out if I use meds, but I haven’t added anything yet. Just doing PWCs and hoping to get some answers before anything gets worse .

Don't know about glow-diseases.

I can feel distain dripping from the few words in your response. No need to reply if you have nothing to add. Thank you.

That said, I don’t think there’s any such thing as a “Glo-Disease”. The Glofish are simply brighter-colored variations of the natural species. Maybe a better way to have asked my question concerning their symptoms would be to say, “Corydoras Aeneus color getting darker…” the white skirt tetra is not even a GloFish. It’s just a regular, run-of-the-mill, naturally-occurring tetra species.

 

I have both glo-fish and bronze versions of cory and I have not encountered the head darkening that you've seen. The lack of search results also indicates that it might be sort of a false flag, symptoms wise. Ich does seem to start in the gills, perhaps the irritation is causing the color change? Ich-X (for example) seems to be effective and relatively safe and two of your tetras are showing signs, so I would treat them. These particular corys can withstand a fairly wide temperature range, Google says 68-82F, so I wouldn't be too worried about raising it a bit depending on what you normally keep the tank at.

 

I have both glo-fish and bronze versions of cory and I have not encountered the head darkening that you've seen. The lack of search results also indicates that it might be sort of a false flag, symptoms wise. Ich does seem to start in the gills, perhaps the irritation is causing the color change? Ich-X (for example) seems to be effective and relatively safe and two of your tetras are showing signs, so I would treat them. These particular corys can withstand a fairly wide temperature range, Google says 68-82F, so I wouldn't be too worried about raising it a bit depending on what you normally keep the tank at.

Thanks Chiz! I just wanted to confirm that it is, in fact Ich. I’m pretty sure now that it is, as the tetras are rubbing against the glass. I can’t find Ich-X locally anywhere. The earliest I can get it if I order it is Friday, if I pay expedited shipping. I will do that if it is the best option for the corys. I’m just worried about waiting that long to start treatment? The only things I can find locally are API Super Ick Cure, Tetra Ick Guard, and some kind of “all natural” product from Petco called Imagitarium Parasite Remedy. I actually have some of the API and Tetra products on hand, but I’m not sure how safe they are for scaleless fish like Corys. Some people suggest a half-dose if you have corys. A lot of the advice I see online says to raise the temp to at least 86°F and leave it there for 2 full weeks to kill the Ich, but that is obvs higher than normal range for Corys. I’m not sure what the best option is to treat the Ich and protect my corys? I love the little guys, and hate to lose them.

 

The most effective treatment seems to be malachite green, so a product with that would be best. Ich-X claims it has a 'milder' version of malachite green, which is supposed to be safer for corys, snails and inverts, but there are many opinions as you are discovering! If your products have malachite green, I would treat with that, but possibly a smaller dose. I have some 3 year old bronze corys that run as cold as 67-68 in the winter and up to 80 in the summer months, but the change is very gradual. Opinions differ on temperature for ich too, but with yours at 78, I would not be afraid to nudge it up to 80, 82 and even 84 after a day or two. Increasing surface agitation by adjusting the filter or adding an air stone will be a BIG help with fish comfort in higher temperatures. And, lastly, make sure to remove the carbon while treating.

 

The most effective treatment seems to be malachite green, so a product with that would be best. Ich-X claims it has a 'milder' version of malachite green, which is supposed to be safer for corys, snails and inverts, but there are many opinions as you are discovering! If your products have malachite green, I would treat with that, but possibly a smaller dose. I have some 3 year old bronze corys that run as cold as 67-68 in the winter and up to 80 in the summer months, but the change is very gradual. Opinions differ on temperature for ich too, but with yours at 78, I would not be afraid to nudge it up to 80, 82 and even 84 after a day or two. Increasing surface agitation by adjusting the filter or adding an air stone will be a BIG help with fish comfort in higher temperatures. And, lastly, make sure to remove the carbon while treating.

Thanks again Chiz! Jw if I should order the Ich-X or Paraguard and wait on it to get here or go ahead and start treating with something else before it gets worse? A lot of advice says to do either higher temp or meds, but not both. I wonder if that’s good advice with the corys?

 

Sorry for the delay- I am not a believer in heat alone to treat ich. I can't really guess as to how bad it is, but if you have malachite green on hand, I would probably add a smaller dose of that today, rather than wait. However, it has been 48 hours since your initial post. Are the symptoms rapidly increasing? Hopefully you have not lost any others.

*I am not an ich expert and was hoping other, more knowledgeable members would help, but crickets...

 

Sorry for the delay- I am not a believer in heat alone to treat ich. I can't really guess as to how bad it is, but if you have malachite green on hand, I would probably add a smaller dose of that today, rather than wait. However, it has been 48 hours since your initial post. Are the symptoms rapidly increasing? Hopefully you have not lost any others.

*I am not an ich expert and was hoping other, more knowledgeable members would help, but crickets...

I was hoping for that too. Thanks for your help though!

I was hoping for that too. Thanks for your help though!

I haven’t lost any others. I’ve been doing PWCs though. The tetras’ behavior is not really normal, otherwise I wouldn’t even be that worried. It still doesn’t look like the tiny little white “salty” spots I see in pictures of Ich either. The spots that I see seem to be bigger and not nearly as many. I’m still not sure if I should be treating for Ich or fungus or use something that covers both, but not sure what is safe for the corys .

 

I was hoping for that too. Thanks for your help though!

I had an ich outbreak I caught early and treated with heat (86 degrees) and salt, yet I see you don’t want to use salt bc of the cories. I looked on here to find similar situations (as yours) and didn’t have much luck, yet I can say when I caught ich early I didn’t need meds. I am also commenting on this to bump it and I hope you can figure it out!!

 

I had an ich outbreak I caught early and treated with heat (86 degrees) and salt, yet I see you don’t want to use salt bc of the cories. I looked on here to find similar situations (as yours) and didn’t have much luck, yet I can say when I caught ich early I didn’t need meds. I am also commenting on this to bump it and I hope you can figure it out!!

Thank you!