90 Gallon Tank Corydoras discoloration

Hi,
Corydoras developed some discoloration. They act normal, chasing and feeding. I redirected the filter model to create more flow in the tank and now have lots of small particles floating. Pic attached. Are corys sick ? Do I need to medicate or just keep changing water ( just did 40% water change).
6 corydoras Julius
8 kuhli
4 electric blue ram
2 golden eye cichlid
2 sailfin molly
1 electric blue acara
I use ferts ( seachem) and co2, I also dosed with sera kh/ph plus. Juwel rio 350, 2x bioflow L, Planted community Tank is cycled. Parameters are normal. Ph 6.8 GH 6 kh3 no ammonia, nitrite or nitrate.

 

How long has the tank been established, how many water changes do you do, how big is the tank? Are they all showing this behaviors. Sounds like water issue but parameters read fine did you test before the water change? Could be a bacterial infection, how does all their barbells look?

 

Closing on 2 months now, Weekly water change, parameters are the same, been stable for the past 2 weeks. Only three has it , the other three look fine. This guy has it the worst.

How long has the tank been established, how many water changes do you do, how big is the tank? Are they all showing this behaviors. Sounds like water issue but parameters read fine did you test before the water change? Could be a bacterial infection, how does all their barbells look?

90 gallon ( 350 liter )

Closing on 2 months now, Weekly water change, parameters are the same, been stable for the past 2 weeks. Only three has it , the other three look fine. This guy has it the worst.
90 gallon
Few snails
Ghost shrimp and Amano shrimp
I use api test kit
2 x filter
Had algae bloom 2 days ago ( brownish hair algae on moss )

 

Honestly it’s hard to say. If I were you I’d stop dosing things changing the water and just keep it stable and consistent. Stop dosing anything except light ferts and just water changes for a few weeks and see if that helps. It’s all I can think of.

It looks like water quality to me and a slim chance of some sort of infection. I assume your treating the water during water changes. I personally think it’s a water issue.

 

Yeah, I stopped dosing, will keep changing water and hope for the best. If it’s gets worse or Cory stop eating I will seek some advise on how to medicate the whole tank, will hard to isolate the corys since they have plenty of space to hide

 

Update, water parameters are stable, kept on changing water, no new infection on other Corys.. this guy had it the worst. Can someone advise on the condition and what is needed , like meds ?

 

Could be bacterial or fungal.

pH/KH plus is absolutely useless for all the species you keep except the Mollies (You should think about rehoming these and lowering the pH permanently for the rest.). Because all your other fish prefer water BELOW your pH, 6.0 to 6.5 would be best. I would be wary with a nitrate reading of 0 if the tank is actually cycled, but that's secondary, as you don't report any signs of ammonia/nitrite pikes.

Try high volume waterchanges (50%) every other day for a week plus indian almond leaves and/or alder cones. If it's bacterial this should show betterment within that week. If not it's probably a fungus.

And PLEASE use the template for disease cases, as this would probvably answer some questions that were not asked yet. Fish Emergency Template | Freshwater Fish Disease and Fish Health Forum | 376562

Could you please post a picture of the whole tank? Often problems like these are due to wrong/bad conditions. Often people don't even know if something is fundamentally wrong.

 

Could be bacterial or fungal.

pH/KH plus is absolutely useless for all the species you keep except the Mollies (You should think about rehoming these and lowering the pH permanently for the rest.). Because all your other fish prefer water BELOW your pH, 6.0 to 6.5 would be best. I would be wary with a nitrate reading of 0 if the tank is actually cycled, but that's secondary, as you don't report any signs of ammonia/nitrite pikes.

Try high volume waterchanges (50%) every other day for a week plus indian almond leaves and/or alder cones. If it's bacterial this should show betterment within that week. If not it's probably a fungus.

And PLEASE use the template for disease cases, as this would probvably answer some questions that were not asked yet. Fish Emergency Template | Freshwater Fish Disease and Fish Health Forum | 376562

Could you please post a picture of the whole tank? Often problems like these are due to wrong/bad conditions. Often people don't even know if something is fundamentally wrong.

Whybis a Ph of 6,8 so bad ?

Are you using a waterconditioner with Aloe Vera ?

 

Thanks for advise.
What is the water volume of the tank? 90 gallons
How long has the tank been running? 2 months
Does it have a filter? Yes , 2 bioflow Large with 1000 l/he pumps.
Does it have a heater? Yes
What is the water temperature? 80-79
What is the entire stocking of this tank? (Please list all fish and inverts.)
6 corydoras jullis
6 kuhli loaches
4 electric blue ram
2 goldeneye cichlid
2 black sailfin molly
1 electric blue acara ( still small )
1 Ghost shrimp
10 amano shrimps
5 Snails

Maintenance
How often do you change the water? Weekly
How much of the water do you change? 30%
What do you use to treat your water? Prime
Do you vacuum the substrate or just the water?
Aqua soil
*Parameters - Very Important
Ph 6.8, ammonia nitrate and nitrite nearly 0 , GH 7 and KH 3. Stable no changes
Did you cycle your tank before adding fish? Yes
What do you use to test the water?Api kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.

Ammonia:
Nitrite:
Nitrate:
pH:

Feeding
How often do you feed your fish? Twice a day
How much do you feed your fish?
What brand of food do you feed your fish? Sera, hikari, tetra, frozen fish food, ocean nutritions and some shrimp
Do you feed frozen or freeze-dried foods? Both

Illness & Symptoms
How long have you had this fish? 1 month
How long ago did you first notice these symptoms? 4 days ago
In a few words, can you explain the symptoms? Discoloration on skin
Have you started any treatment for the illness? No just water changes and stopped dosing ferts and water treatments
Was your fish physically ill or injured upon purchase? No
How has its behavior and appearance changed, if at all? No, feeding and swimming normally

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)
Noticed three corys with discolorations on skin, two minor and one sever. Stopped dosing ferts and water treatment ( sera kh/ph plus ). Did 2 water changes 40% each.

Whybis a Ph of 6,8 so bad ?

Are you using a waterconditioner with Aloe Vera ?

I use prime and since I noticed the issue I added api stress zyme and stress coat. The tank KH is low and I wanted to avoid ph crash . Not sure now of it was the right thing to do

 

pH crashes belong to the realm of legend. Many many aquarists have a KH of 0 and still experience no crashes in tanks running like that for years. All events of sudden drops were connected to malfunctioning CO2 units or grossly overdosing pH-down products.

Better stop using zyme and coat, they do nothing for your fish, especially in this case.

I use prime and since I noticed the issue I added api stress zyme and stress coat. The tank KH is low and I wanted to avoid ph crash . Not sure now of it was the right thing to do

Some tipps and hints what could be done better:

Only feed once a day and do 1-2 fast days a week. Also: In case you feed flakes, stop feeding those, they are often detrimental to water quality. Also take the time your fish need to eat all you feed per feeding. If they are still at it after 5 minutes it's way too much.
Up the waterchanges generally to 50% a week.
Put in more plants and maybe use some floating plants to slightly dim the lights.
Stop using any synthetic water additives except water conditioner and (if necessary) fertilizers.

As already mentioned, try a sequence of several big waterchanges in a week and see if there are any changes to the condition. If not I stand by my conclusion that it could be a fungus.

Also: When it comes to Cories, definitely listen to DoubleDutch.

 

T

pH crashes belong to the realm of legend. Many many aquarists have a KH of 0 and still experience no crashes in tanks running like that for years. All events of sudden drops were connected to malfunctioning CO2 units or grossly overdosing pH-down products.

Better stop using zyme and coat, they do nothing for your fish, especially in this case.



Some tipps and hints what could be done better:

Only feed once a day and do 1-2 fast days a week. Also: In case you feed flakes, stop feeding those, they are often detrimental to water quality. Also take the time your fish need to eat all you feed per feeding. If they are still at it after 5 minutes it's way too much.
Up the waterchanges generally to 50% a week.
Put in more plants and maybe use some floating plants to slightly dim the lights.
Stop using any synthetic water additives except water conditioner and (if necessary) fertilizers.

As already mentioned, try a sequence of several big waterchanges in a week and see if there are any changes to the condition. If not I stand by my conclusion that it could be a fungus.

Also: When it comes to Cories, definitely listen to DoubleDutch.

Thanks guys