Added new filter to tank - EVERYTHING died.

[Pureguava]

hi.

20 gal tank

10 cardinals
3 khuli loaches

planted tank / co2 and UV.


had been set up for 6 months. never a single death. Wanted a larger filter so added a new one (canister) in series to the old one last night. Woke up in the morning and all are dead. Every single one of them! i feel pretty low.

my guess some toxin in the new filter? If so how long should i wait until i put some more fish in. should i run a big ol' bag of activated carbon in there for a few days?

water parameters were all good - ph - 6.5 dh/kh close to 0. Ammonia / nitrites / nitrates 0. Temp 26.5c.

thanks all.

 

[shadowstars123]

hi.

20 gal tank

10 cardinals
3 khuli loaches

planted tank / co2 and UV.


had been set up for 6 months. never a single death. Wanted a larger filter so added a new one (canister) in series to the old one last night. Woke up in the morning and all are dead. Every single one of them! i feel pretty low.

my guess some toxin in the new filter? If so how long should i wait until i put some more fish in. should i run a big ol' bag of activated carbon in there for a few days?

water parameters were all good - ph - 6.5 dh/kh close to 0. Ammonia / nitrites / nitrates 0. Temp 26.5c.

thanks all.

Did you rinse everything before setting it up?

 

[Homedog98]

You killed all your beneficial bacteria. Your fish probably died because of an ammonia spike.

 

[Mr. Limpet]

hi.

20 gal tank

10 cardinals
3 khuli loaches

planted tank / co2 and UV.


had been set up for 6 months. never a single death. Wanted a larger filter so added a new one (canister) in series to the old one last night. Woke up in the morning and all are dead. Every single one of them! i feel pretty low.

my guess some toxin in the new filter? If so how long should i wait until i put some more fish in. should i run a big ol' bag of activated carbon in there for a few days?

water parameters were all good - ph - 6.5 dh/kh close to 0. Ammonia / nitrites / nitrates 0. Temp 26.5c.

thanks all.

Sorry to hear about your loss .

Was the filter "brand new", or did you buy it used? A new filter shouldn't have been an issue, but like anything else you get, rinse and prep is important. A used one would need extensive cleaning IME.

There's something else going that caused it IMO.

 

[eco23]

Sorry to hear about your loss .

Was the filter "brand new", or did you buy it used? A new filter shouldn't have been an issue, but like anything else you get, rinse and prep is important. A used one would need extensive cleaning IME.

There's something else going that caused it IMO.

Agreed. Unless some employee poisoned the inside of it...a little dust seems like worst case scenario. At least nothing that would have wiped out the stock overnight IMO.

 

[shadowstars123]

You killed all your beneficial bacteria. Your fish probably died because of an ammonia spike.

Unless I read his post wrong, I believe he ran his new one along with his old filter, and he stated all of his readings were 0.

 

[Kat1103]

Zero nitrates? I would think u would have some in a six month old tank unless u aren't cycled. If u didn't, u should have kept the old filter to seed the new one. U don't want to kill all that good bacteria or let it go to waste!

 

[Homedog98]

Unless I read his post wrong, I believe he ran his new one along with his old filter, and he stated all of his readings were 0.

The OP says nothing about running the filter along with his old one... So with 0 nitrates it sounds like he started cycling all over again.

 

[adadkins1]

The OP says nothing about running the filter along with his old one... So with 0 nitrates it sounds like he started cycling all over again.

"Wanted a larger filter so added a new one (canister) in series to the old one last night."

The way I read this is the new filter was added in tandem with the old filter. I do not think this should have effected they cycle. The 0 Nitrates is not too surprising, if the tank is planted heavily enough it could be kept at a really low level.

 

[ejaramillo01]

The OP says nothing about running the filter along with his old one... So with 0 nitrates it sounds like he started cycling all over again.

Could be, we don't even know if the tank was fully cycled. But all dead in one night??, IMO, is something else rather than ammonia spike.
Test your water again, maybe something in the " motor / impeller " is leaking, like oil??

 

[shadowstars123]

Could be, we don't even know if the tank was fully cycled. But all dead in one night??, IMO, is something else rather than ammonia spike.
Test your water again, maybe something in the " motor / impeller " is leaking, like oil??

I don't believe fiters use oil; but rather water as a lubricant/coolant. Ever see the do not run dry sticker? But i might be wrong. Maybe it was a disease? But idk. All dead in a day?

 

[mudraker]

I don't believe fiters use oil; but rather water as a lubricant/coolan

Cannister filters require lubricants on the seals.

My guess is there is a problem with the UV. I have heard of these running too high and killing off all bacteria, not just the bb associated with keeping the tank cycled.

I don't run one myself, but I have read about these types of problems before.

The UV (in a quality cannister) can be adjusted up and down and if its run too high, it can kill of all beneficial microbes to the point the water is sterile and kills off the fish too.

It is why you shouldn't use only distilled water in an aquarium.

This is my educated guess anyway.

 

[shadowstars123]

Cannister filters require lubricants on the seals.

My guess is there is a problem with the UV. I have heard of these running too high and killing off all bacteria, not just the bb associated with keeping the tank cycled.

I don't run one myself, but I have read about these types of problems before.

The UV (in a quality cannister) can be adjusted up and down and if its run too high, it can kill of all beneficial microbes to the point the water is sterile and kills off the fish too.

It is why you shouldn't use only distilled water in an aquarium.

This is my educated guess anyway.

Well he said it had been set up for 6 months, so wouldn't the fish be long dead?

 

[ejaramillo01]

hi.

20 gal tank

10 cardinals
3 khuli loaches

planted tank / co2 and UV.


had been set up for 6 months. never a single death. Wanted a larger filter so added a new one (canister) in series to the old one last night. Woke up in the morning and all are dead. Every single one of them! i feel pretty low.
my guess some toxin in the new filter? If so how long should i wait until i put some more fish in. should i run a big ol' bag of activated carbon in there for a few days?

water parameters were all good - ph - 6.5 dh/kh close to 0. Ammonia / nitrites / nitrates 0. Temp 26.5c.

thanks all.

No, the OP said that the filter was added just the night before, he added the canister filter..... the tank have been running for 6 months with a smaller (different ) filter.

 

[toddnbecka]

Adding a new filter wouldn't kill the fish overnight regardless of whether all the media was fresh, but an imbalance of CO2/O2 would account for it.

 

[fort384]

An imbalance of CO2/O2? So you think that adding the extra filter was just coincidence, and the CO2 system malfunctioned?

OP: Did you check your CO2 upon discovery of the mass die off?

I have no idea what caused this, but I don't think it had anything to do with the nitrogen cycle, or with the UV sterilizer.

 

[toddnbecka]

From the info the OP posted that seems like the most likely cause; an ammonia spike wouldn't hit hard or fast enough in a planted tank to kill everything overnight.

 

[fort384]

Agreed on the ammonia. Seems like a big coincidence that the new filter didn't have something to do with this...

 

[Rokuzachi]

I agree on the ammonia as well. In the past I have egregiously overstocked a small-ish planted tank and even then it took over 24 hours for the ammonia to go up by .25.

 

[shadowstars123]

I'm just throwing this out there, but do you have any kids? Maybe they dumped something in the tank?