All my fish are dying, what's going on?

[Plec123]

Have you tested your water?

Yes

If yes, what is your ammonia?

0

If yes, what is your nitrite?

0

If yes, what is your nitrate?

10

If I did not test my water...

1. ...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.

Do you do water changes?

Yes

What percentage of water do you change?

31-40%

How frequently do you change your water?

Every week

If I do not change my water...

1. ...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.

So, kind of a long story but here goes.
And in advance, yes, I am aware that I should have a quarantine tank.

I bought a wildcaught pleco from Discus Madness and did not see until it was in my tank that it had anchor worms. I didn't catch this until a couple days after as I initially thought the worms were just the fish's odontodes flaking off after being bagged or due to stress.
He wasn't eating and I noticed my other fish scratching themselves a bit, so I did a couple water changes over the course of 3 days to reduce nitrates and manually removed the worms from the pleco once i realized what they were. I also ordered Dimilin-X online which was dosed on Thursday last week. By thursday night, the pleco was floating on occasion and my other fish were looking splotchy, like they had excess mucus. My hoplo cat and several other plecos had numerous young worms on them.

Friday morning, the pleco is floating, bloated, and of course, dead. The other fish are all still eating, though they're lethargic and their color is off.

2nd dose of Dimilin-X on sunday. Again, everyone is eating and though they seem a bit agitated no one looks horribly ill.

This morning, I found my pike cichlid, myersi cichlid, para pleco, three beacon pleco, and green phantom pleco all dead. My two acaras are hiding, ripped fins, very dark coloration, patchy mucus. Hardly eating. The living plecos are a little antsy but look mostly okay. Anchor worms are all gone on the hoplo.

I went to my other lfs and picked up API general cure as well as prazi in case the two doses of general cure don't cure my fish. Put in the first dose of general cure today. I figure the metronidazole and prazi combo should nuke whatever bug is causing this.
I assume what i missed initially would be internal parasites passed from the pleco to the rest of my fish. Could anything else be causing this? I thought pH shock from the water changes mught have done it (my tank normally runs 6.4 and the tap is 7.4-7.5) but to kill this many fish it seems unlikely.

Am i missing anything else? I'm so bummed, I had some of these guys for quite a while.

 

[The Morning]

I can’t answer your questions but really sorry to hear about this. Tough story. Good luck with the rest of your stock.

 

[Abeer_Sanduja]

Firstly any sort of wild fish can have several parasites may be internal or external. And anchor works are only visible when they are about to die or at the last stage in their life cycle so that means they had laid their eggs beforehand. You should keep the fish that look better than others in a separate Tank and treat them there. Best of luck. You could also put aquarium salt to reduce stress and do several water changes in a single day to maintain pristine water quality.

 

[Abeer_Sanduja]

Along with this if the fish were diseased the ph shock would have out then in greater stress and weekend their immune system.

 

[kno4te]

Swing in ph can cause something like this.

 

[Plec123]

Swing in ph can cause something like this.

Would you recommend trying to neutralize the pH or bring it bac down, or just maintain it high at this point? My tap water has the high pH so frequent water changes will just keep it high.

Thanks for the replies guys.

 

[Plec123]

Also, could using RO water in the future help me prevent the pH from fluctuating so much with water changes? I've never had an RO unit so that wold be a whole new learning process.

 

[kno4te]

Would you recommend trying to neutralize the pH or bring it bac down, or just maintain it high at this point? My tap water has the high pH so frequent water changes will just keep it high.

Thanks for the replies guys.

Also, could using RO water in the future help me prevent the pH from fluctuating so much with water changes? I've never had an RO unit so that wold be a whole new learning process.

An rodi system will work to reduce ur ph. It’ll have to be mixed with dechlorinatored tap water. You’ll have to figure how much of each will get you the desired tds. Once that’s done and you can replicate it then yes the ph can be stable.

Other option is keep ur ph and get fish that have no issues tolerating it. Even local bred fish will work since tolerating ur water.

 

[duanes]

Too late for the OP, but to all others reading this.... a proper quarantine in a separate tank, would have avoided this entire scenario.

As far as pH goes, a rise from 6.4 to 7.4 (or vice versa) would not usually be enough to kill healthy fish.
But in an unhealthy condition, it is possible.
One of the reasons for frequent water changes, is to maintain a stable pH.
I'm wondering why the tanks pH is 6.4, yet the tap is 7.4, with a proper water change schedule the tanks pH should only drop a few tenths under the tap water pH.
Or........
Are you intentionally trying to keep it more acidic?

I consider a 30-40% water change once per week, quite a wimpy schedule, to maintain tank stability.
Are you also cleaning filter media with each water change?
If there is too much gunk in the filter, this could be the reason the tank pH drops, because acids from metabolism of gunk use up the new waters buffering capacity.

As said above (along with the external parasites), it could be something bacterial, something the other meds are not effective against.
The injuries from the Lernaea are places where secondary infections can take hold.
And sometimes cramming medications into a tank, can do more harm than good.

I cured my tank of introduced Lernaea by removing them, and using salinity.
I find salt can be just as effective, and less hard on the fish, than using medication.

I believe we talked about this in your other thread.
Using RO could allow even more drastic pH fluctuations.

 

[Plec123]

Too late for the OP, but to all others reading this.... a proper quarantine in a separate tank, would have avoided this entire scenario.

As far as pH goes, a rise from 6.4 to 7.4 (or vice versa) would not usually be enough to kill healthy fish.
But in an unhealthy condition, it is possible.
One of the reasons for frequent water changes, is to maintain a stable pH.
I'm wondering why the tanks pH is 6.4, yet the tap is 7.4, with a proper water change schedule the tanks pH should only drop a few tenths under the tap water pH.
Or........
Are you intentionally trying to keep it more acidic?

I consider a 30-40% water change once per week, quite a wimpy schedule, to maintain tank stability.
Are you also cleaning filter media with each water change?
If there is too much gunk in the filter, this could be the reason the tank pH drops, because acids from metabolism of gunk use up the new waters buffering capacity.

As said above (along with the external parasites), it could be something bacterial, something the other meds are not effective against.
The injuries from the Lernaea are places where secondary infections can take hold.
And sometimes cramming medications into a tank, can do more harm than good.

I cured my tank of introduced Lernaea by removing them, and using salinity.
I find salt can be just as effective, and less hard on the fish, than using medication.

I believe we talked about this in your other thread.
Using RO could allow even more drastic pH fluctuations.

I was trying to keep it more acidic initially as I noticed all of my cichlids really showed improved behavior and coloration when the pH was lower. Because of this, I had been doing water changes less frequently to attempt to maintain a more acidic pH. Once I bumped up my water change schedule, they seemed to become less content.

I don't clean the filters as often as I should, I will admit that. Perhaps the buildup inside them is affecting the water's buffering capacity. I'm sure all of the driftwood in the tank isn't helping matters either.

We did talk about using salt to halt the Lernaea infestation in my other thread, but I doubted my ability to figure out the proper dosage and it seemed like the Dimilin would kill the worms without question, so I went that route. I didn't doubt that the salt would work, I was just looking for what seemed to be the quickest solution in my eyes.