dying corys?

[robyndarlene]

I have a 75gal freshwater with 2 pumps, (90g)&(30g) pump.
Stocked with guppies, a severum, a tetra, corys and loaches. I have sand for substrate.
About two days ago I woke up to three corts hardly breathing, and two dead loaches. No Ich no fin rot. Whats going on? Their continuing to die
Its like their hearts explode or something! They get super red around the gills then bam their dead

 

[Cactuspixie]

I have a 75gal freshwater with 2 pumps, (90g)&(30g) pump. Stocked with guppies, a severum, a tetra, corys and loaches. I have sand for substrate. About two days ago I woke up to three corts hardly breathing, and two dead loaches. No Ich no fin rot. Whats going on? Their continuing to die Its like their hearts explode or something! They get super red around the gills then bam their dead

Being bottom dwellers, cories and loaches are very sensitive to any build up of detritus on the bottom. It's easy for them to pick up infections, but check your ammonia, nitrites and nitrates, as toxin levels may be causing the damage to their gills. Also the Sev will most likely nip at them. I put a small sev in my 170g kuhli and pleco tank, and the poor kuhlis are too terrified to show their faces now. The sev spends his days slowly cruising the tank with an eagle eye for the slightest movement. Then he shows how quick he can be. Stress makes fish more susceptible to illness.

 

[robyndarlene]

Being bottom dwellers, cories and loaches are very sensitive to any build up of detritus on the bottom. It's easy for them to pick up infections, but check your ammonia, nitrites and nitrates, as toxin levels may be causing the damage to their gills. Also the Sev will most likely nip at them. I put a small sev in my 170g kuhli and pleco tank, and the poor kuhlis are too terrified to show their faces now. The sev spends his days slowly cruising the tank with an eagle eye for the slightest movement. Then he shows how quick he can be. Stress makes fish more susceptible to illness.

I can assure you my gentle giant isn't the cause of this. My loaches swim freely and he doesn't even touch the fry. I think it is a nitrate spike. I did a half watee change yester day. I had been out of town for a month and it had been a month since the last water change. Would that have caused it? I'm scared

 

[Cactuspixie]

I can assure you my gentle giant isn't the cause of this. My loaches swim freely and he doesn't even touch the fry. I think it is a nitrate spike. I did a half watee change yester day. I had been out of town for a month and it had been a month since the last water change. Would that have caused it? I'm scared

Definitely. In order to have a nitrate spike you have to first have an ammonia spike, followed by a nitrite spike. Depending on how much bio filtration you have, the first two spikes may not have been large or lasted long, but the nitrates would have kept building.
I think it was a nitrate spike that killed my 2 big beautiful Siamese algae eaters the other night.

 

[robyndarlene]

Is it going to continue affecting them? I've had three more deaths today.. ones on his way out. I have three that are still acting fine. If it was a parasote I think all my fish would have it including my highfins. Will this water change have fized the issue?

 

[Cactuspixie]

Is it going to continue affecting them? I've had three more deaths today.. ones on his way out. I have three that are still acting fine. If it was a parasote I think all my fish would have it including my highfins. Will this water change have fized the issue?

If fish are still dying you haven't fixed the issue. What are your test results? You need to continue with water changes until your ammonia and nitrites are zero and your nitrates are at or under 20ppm.
How often did you used to do pwc and how much did you change before you went away?
Did you clean the filter and substrate before you left? Do you think they were over fed in your absence?

 

[robyndarlene]

If fish are still dying you haven't fixed the issue. What are your test results? You need to continue with water changes until your ammonia and nitrites are zero and your nitrates are at or under 20ppm.
How often did you used to do pwc and how much did you change before you went away?
Did you clean the filter and substrate before you left? Do you think they were over fed in your absence?

I did a full water change just prior to leaving. I added all new sand about 2 weeks prior. I had a dead plant in my t ank when I got back and I think they could have been over fed a bit. I'm not quite sure.
I have no way of testing my water for at least a week so I will continue with water changes. Will cleaning deco and substrate also help? The fish that have died are the ones that were already acting odd prior to the change I did yesterday.

 

[robyndarlene]

I just got all new filter cartridges before I left. I have aqueon filters, over the tank type. Its an acrylic tank if that helps.

 

[Coursair]

I just got all new filter cartridges before I left. I have aqueon filters, over the tank type. Its an acrylic tank if that helps.

You may have over cleaned before you left. Doing a massive water change plus changing all the filter media may have removed too much of the BB and you had a mini cycle.

Normally I do PWCs every week. Once a month lets things build up too much.