One fish dead the other not looking good help!!

[LexiLex888]

So yesterday evening I did a water change on my goldfish tank (40 gallons) that only had two small goldfish in it.

They seemed to be fine yesterday but this morning I woke up to one dead and the other laying on the bottom of the tank and it looks like his skin is peeling off?

I do this water change every week on Wednesday and they’ve never reacted like this before. What did I do wrong??

Is there anything I can do do save the last goldfish???

 

[PhantomCarp]

Did you add decloranator to the new water that you added?

 

[LexiLex888]

Did you add decloranator to the new water that you added?

Yes I did. And the water I added was the same temperature as the water removed.

 

[Byron]

The photos look like excess fish slime which means soomething in the water is irritating them. Canyou test for ammonia, nitrite and nitrate, and if yes, what are those numbers.

 

[LexiLex888]

The photos look like excess fish slime which means soomething in the water is irritating them. Canyou test for ammonia, nitrite and nitrate, and if yes, what are those numbers.

Yes I’ll test it.

 

[Colin_T]

it's just excess mucous.

check the tank water for ammonia, nitrite, nitrate and pH like Byron said.
check the tap water for the same things.

make sure you use a bucket specifically for the fish and not any bucket from around the house.

make sure you don't have any oil, grease, cream, soap, etc, on your hands when feeding or working in the tank.

do another water change (50-75%) and gravel clean the substrate.

add 2 heaped tablespoons of rock salt, sea salt, or swimming pool salt for every 20 litres of tank water. Keep the salt in there for 2 weeks.

 

[LexiLex888]

it's just excess mucous.

check the tank water for ammonia, nitrite, nitrate and pH like Byron said.
check the tap water for the same things.

make sure you use a bucket specifically for the fish and not any bucket from around the house.

make sure you don't have any oil, grease, cream, soap, etc, on your hands when feeding or working in the tank.

do another water change (50-75%) and gravel clean the substrate.

add 2 heaped tablespoons of rock salt, sea salt, or swimming pool salt for every 20 litres of tank water. Keep the salt in there for 2 weeks.

The tank is at:
pH is 7.8
Ammonia is 0.50 ppm
Nitrite is 2.0 ppm (or 5.0 ppm I couldnt tell)
is 0 ppm
Nitrate is a 0 ppm

The tap water is at:
pH is 7.4
Ammonia is 0.50 ppm
Nitrite is 0 ppm
Nitrate is 0 ppm

Are those numbers bad? I know the nitrite should be at 0, right?

Yes I use a special fish bucket only used for their tank.

I will do the water change and salt addition as soon as can today.

 

[Byron]

The fish are having serious issues with the nitrite especially and the ammonia. As this tank has been running for a time, something must have occurred this last water change to cause the nitrification cycle to fall apart. Did you perhaps replace the filter media at the same time?

The immediate thing is to do a major water change (70-75% of the tank's volume) and use conditioner. This should reduce the ammonia/nitrite. A bacterial supplement, any one here, would also help as it helps to re-establish the bacteria. I am assuming there are no live plants--if there were, they would take care of this automatically. Test each day and do the same water change until ammonia and nitrite are zero. This may save the remaining fish, though we cannot know how much damage internally may have been done.

 

[LexiLex888]

The fish are having serious issues with the nitrite especially and the ammonia. As this tank has been running for a time, something must have occurred this last water change to cause the nitrification cycle to fall apart. Did you perhaps replace the filter media at the same time?

The immediate thing is to do a major water change (70-75% of the tank's volume) and use conditioner. This should reduce the ammonia/nitrite. A bacterial supplement, any one here, would also help as it helps to re-establish the bacteria. I am assuming there are no live plants--if there were, they would take care of this automatically. Test each day and do the same water change until ammonia and nitrite are zero. This may save the remaining fish, though we cannot know how much damage internally may have been done.

Yes I did replace the filter last night! Yikes I didnt know it could hurt them this bad.

Ok! I’ve just done a 70% water change and I’m now adding pre-conditioned water into the tank. I suck!!! I had no idea this would hurt them so bad.

I’ll keep doing the water change and keep testing it everyday until ammonia and nitrite is at 0.

So, if I were to have live plants in the tank, they would immediately take care of the problem? If so, in the future, should I look into getting live plants to help this from happening again?

 

[Byron]

Yes I did replace the filter last night! Yikes I didnt know it could hurt them this bad.

Ok! I’ve just done a 70% water change and I’m now adding pre-conditioned water into the tank. I suck!!! I had no idea this would hurt them so bad.

I’ll keep doing the water change and keep testing it everyday until ammonia and nitrite is at 0.

So, if I were to have live plants in the tank, they would immediately take care of the problem? If so, in the future, should I look into getting live plants to help this from happening again?

What happened when you removed the filter is you removed most of the nitrifying bacteria. Some live in the substrate, but in a tank like this one with gldfish which are major wate machines the filter is primary.

Live plants that are fast growing take up ammonia and rapidly. So they would have helped here. Goldfish do eat plants though, and floating are the best for the ammonia issue.

 

[LexiLex888]

What happened when you removed the filter is you removed most of the nitrifying bacteria. Some live in the substrate, but in a tank like this one with gldfish which are major wate machines the filter is primary.

Live plants that are fast growing take up ammonia and rapidly. So they would have helped here. Goldfish do eat plants though, and floating are the best for the ammonia issue.

Oh man that’s really good to know, thank you.

The only reason I changed the filter in the first place is because it was just covered in algae and because of that the filter’s biowheel isn’t turning.
What should I do when the filter gets so clogged up with algae? And how am I supposed to stop the algae from growing so fast?

 

[Byron]

Oh man that’s really good to know, thank you.

The only reason I changed the filter in the first place is because it was just covered in algae and because of that the filter’s biowheel isn’t turning.
What should I do when the filter gets so clogged up with algae? And how am I supposed to stop the algae from growing so fast?

Clean the filter regularly, probably at every water change. Clean is not replace the media. In your situation, rinse the media in a bucket of tank water.

Do a substantial water change once each week, and change 60-70% of the tank water at each. [This is regular, different from the daily changes now to keep ammonia and nitrite down.] Clean in the substrate with the water changer unit to get as much of the organics.

B careful not to overfeed. All fish will eat if food is presented, but they need far less than many imagine. What goes in must come out.

 

[LexiLex888]

Clean the filter regularly, probably at every water change. Clean is not replace the media. In your situation, rinse the media in a bucket of tank water.

Do a substantial water change once each week, and change 60-70% of the tank water at each. [This is regular, different from the daily changes now to keep ammonia and nitrite down.] Clean in the substrate with the water changer unit to get as much of the organics.

B careful not to overfeed. All fish will eat if food is presented, but they need far less than many imagine. What goes in must come out.

Okay, I will start being so much more cautious with the filter and start cleaning it properly! Thank you so much!

I just tested the nitrite and ammonia again and it’s currently at:

nitrite is 2.0 ppm
ammonia is 0.50 ppm

I don’t think it has changed at all since yesterday, is there anything else I can be doing to bring it down other than water changes?

 

[Byron]

Okay, I will start being so much more cautious with the filter and start cleaning it properly! Thank you so much!

I just tested the nitrite and ammonia again and it’s currently at:

nitrite is 2.0 ppm
ammonia is 0.50 ppm

I don’t think it has changed at all since yesterday, is there anything else I can be doing to bring it down other than water changes?

If you can get to a fish store, a bottle of bacterial supplement would help. Tetra's SafeStart is one of the best. But most any will help, Seachem's Stability (I've used this in an emergency), Nutrafin's Cycle, etc.

 

[LexiLex888]

If you can get to a fish store, a bottle of bacterial supplement would help. Tetra's SafeStart is one of the best. But most any will help, Seachem's Stability (I've used this in an emergency), Nutrafin's Cycle, etc.

Ok! I’ll try that as well, thank you!