Fish Flashing/Scratching Regularly

[Twood]

Hi team - my fish are flashing/scratching, and seemingly everything is okay with water conditions (numbers posted below for reference). Its a 75 gallon tank with Geophagus, barbs, and danios. I have never seen the Geophagus scratch/flash, but the barbs and danios do it with regularity - seems like I see one flashing every few minutes. I do regular water changes. Its interesting because I have a separate 40 gallon tank - roughly the same parameters, and I see my Cory cats and guppies flashing/scratching as well in that tank. The fish are all eating, look extremely healthy, no physical signs of disease on them, but I seem them flashing / scratching. Any idea what it might be and how I can fix it?

• pH 7.6
• Nitrates 0
• Hardness 25
• Nitrite 0
• Ammonia 0
• KH/Buffer 80
• Chlorine 0
• Water Temperature 80

[_Eric_]

This one is a little puzzling.  Here’s what I know about causes for flashing.
 

1.  Nitrites:

This is what I’ve experienced most.   Are you using the AC strips for nitrites?  If small enough not to register, it will just fix itself eventually.  The API kits seem to show a tinge of purple even with very small amounts of nitrite so if that is source of the test you can probably rule that out.  I get a small nitrite spike with maracyn.

2.  Parasites or skin bacteria is another source but you should be able to see those eventually.  I would wait for bit in case you see signs of Ich or something before treating so you know how to treat.  If you aren’t able to identify another cause, I would treat for external parasites blindly.

3. Other chemicals in the water that are annoying to the fish.  Sometimes even “aquarium safe” decor will put something in the water that they don’t like for a while or maybe something new in your water supply.  Double check to make sure you are using enough dechlorinator.  If you haven’t added anything lately, you could hold off on the water change longer or do smaller amounts.  With 0 Nitrates you can probably go for a while.  Sometimes fertilizer can build up some elements but your sizeable water changes would have fixed that.  
 

4 quick changes to water parameters.  What is the ph out of the tap?  If that is very different than your tank, it could cause some swings with a 40% change.  May be worth holding off on the water changes for a while to see if it helps.  

4 general stress can cause flashing sometimes.  I would think the temperature could be stressing the danios and corys but the guppies and barbs wouldnt mind 80 degrees.  Since it is in separate tanks I wouldn’t think they would have other similar stress factors.

I bet it is something that will be cured with less frequent and / or less sizeable water changes or your fish have parasites or an external infection.  Just my two cents.  

 

 

Edited July 28, 2023 by _Eric_

[Twood]

On 7/28/2023 at 3:20 PM, _Eric_ said:

This one is a little puzzling.  Here’s what I know about causes for flashing.
 

1.  Nitrites:

This is what I’ve experienced most.   Are you using the AC strips for nitrites?  If small enough not to register, it will just fix itself eventually.  The API kits seem to show a tinge of purple even with very small amounts of nitrite so if that is source of the test you can probably rule that out.  I get a small nitrite spike with maracyn.

2.  Parasites or skin bacteria is another source but you should be able to see those eventually.  I would wait for bit in case you see signs of Ich or something before treating so you know how to treat.  If you aren’t able to identify another cause, I would treat for external parasites blindly.

3. Other chemicals in the water that are annoying to the fish.  Sometimes even “aquarium safe” decor will put something in the water that they don’t like for a while or maybe something new in your water supply.  Double check to make sure you are using enough dechlorinator.  If you haven’t added anything lately, you could hold off on the water change longer or do smaller amounts.  With 0 Nitrates you can probably go for a while.  Sometimes fertilizer can build up some elements but your sizeable water changes would have fixed that.  
 

4 quick changes to water parameters.  What is the ph out of the tap?  If that is very different than your tank, it could cause some swings with a 40% change.  May be worth holding off on the water changes for a while to see if it helps.  

4 general stress can cause flashing sometimes.  I would think the temperature could be stressing the danios and corys but the guppies and barbs wouldnt mind 80 degrees.  Since it is in separate tanks I wouldn’t think they would have other similar stress factors.

I bet it is something that will be cured with less frequent and / or less sizeable water changes or your fish have parasites or an external infection.  Just my two cents.  

 

 

@_Eric_ - thanks so much for the feedback here. I am using the Aquarium Coop strips. Your comment made me think it might be worth getting another test done - I may head to my LFS tomorrow to get a reading from them to see if they are picking up something that I am not. 

Regarding the parasites - that is where my head was. All the fish in the tank came through quarantine and treatment, but you never know for sure right. I may end up going the paracleanse route, and perhaps some Prazi-Pro.

Regarding the water changes, you bring up a good point. I have done a few sizable water changes recently. I am on a well, so my water does not have any chlorine in it. As a result I don't put in any conditioner. I may try adding some conditioner anyway - who knows, maybe there is something else in the water that is upsetting the fish.

I think you are spot on with the regular water changes. Given the fish aren't showing any physical signs of parasite or infection, I am not concerned they are going to die off all of a sudden. I think I am just going to do nothing and continue to watch. If it doesn't get any better in the near future I will likely head down the treating for parasite routes. I'll circle back once I get it figured out. Thanks so much for your thoughtful response.

 

[Mmiller2001]

I’d treat for flukes.

[_Eric_]

On 7/28/2023 at 9:31 PM, Twood said:

@_Eric_ - thanks so much for the feedback here. I am using the Aquarium Coop strips. Your comment made me think it might be worth getting another test done - I may head to my LFS tomorrow to get a reading from them to see if they are picking up something that I am not. 

Regarding the parasites - that is where my head was. All the fish in the tank came through quarantine and treatment, but you never know for sure right. I may end up going the paracleanse route, and perhaps some Prazi-Pro.

Regarding the water changes, you bring up a good point. I have done a few sizable water changes recently. I am on a well, so my water does not have any chlorine in it. As a result I don't put in any conditioner. I may try adding some conditioner anyway - who knows, maybe there is something else in the water that is upsetting the fish.

I think you are spot on with the regular water changes. Given the fish aren't showing any physical signs of parasite or infection, I am not concerned they are going to die off all of a sudden. I think I am just going to do nothing and continue to watch. If it doesn't get any better in the near future I will likely head down the treating for parasite routes. I'll circle back once I get it figured out. Thanks so much for your thoughtful response.

 

Treating the water is worth a shot but that would be surprising since you are on a well.  You will know quickly though.  
 

I would give it a couple of days to a week without a water change and then treat blind for parasites if there are still no signs of what the issue is.  There are some you can’t see that can be a problem so I wouldn’t let it go too long.  

[Twood]

On 7/28/2023 at 11:33 PM, Mmiller2001 said:

I’d treat for flukes.

Thanks @Mmiller2001! Likely headed down this route in short order.

On 7/29/2023 at 9:45 AM, _Eric_ said:

Treating the water is worth a shot but that would be surprising since you are on a well.  You will know quickly though.  
 

I would give it a couple of days to a week without a water change and then treat blind for parasites if there are still no signs of what the issue is.  There are some you can’t see that can be a problem so I wouldn’t let it go too long.  

Thanks @_Eric_ - I am going to test water again, maybe wait another day. If its not resolved, then I am going to start treating for parasites. Do you prefer the Paracleanse, Prazi Pro - or something else?

[_Eric_]

Between those two I’d go with prazi pro.  Praziquantel seems to be more targeted for external parasites.   

[Mmiller2001]

Do you have Plecos in the tank?