Fish dying! Please help!

[lauraleellbp]

All it takes to have a cycling issue is more bioload than the population of N-bacteria in your tank can handle.

My best guess with the current info is that either adding the rasboras triggered a minicycle, and/or the issue is your rather extreme water parameters. The cardinals may not have liked the water hardening, and the harlequins may not have been able to acclimate.

I'd probably bump up the frequency and percentage of your water changes. Maybe 30% 2x/week and see if that will slowly get your tank water stats closer to your tapwater?

I'd also add some good nutrient-hog stem plants to try and counteract that high nitrIte level in your tapwater; hygrophilia, bacopa, hornwort... something along those lines?

[krak256]

This is my tank. I just took the picture. I honestly cannot name all my plants, but I think I have a good amount of stem plants. (Please disregard the breeder net. I have baby shrimp in there )
Attachment 6560

I have java fern, giant hygro, dwarf sagg, vals, hornwort, some swords, anubias, wysteria... and thats all i can name. i dont think my bioload is that high. as you can see, theres not that many fish

[Blue Ridge Reef]

The bioload doesn't look too high from what I can see in the picture. Any chance you're overfeeding?

[Lotsofish]

Perhaps the 6 new harlequins died simply because of transport shock and the two cardinals just died. That is also a possibility.

Still, I think that when you replaced the carbon you somehow upset the bacteria that take care of ammonia and nitrite. Did you clean the filter media in any way that would kill off bacteria? Also possible, the coral might of had some type of contaminate in it that the fish reacted to.

[fishscale]

I just noticed that you said you never found your fish. It is also possible that the dead fish caused a spike that disappeared when the bodies were eaten.

[krak256]

i only found 2 out of 7 bodies, perhaps thats what caused the spike. the harlequins were from petco... if that says anything

[lauraleellbp]

Quarantine, quarantine, quarantine.

I've regretted every single live fish purchase I've ever made from one of the big chain stores. Just my personal experience.

[LS6 Tommy]

High Nitrates are generally a sign of a biologically "dirty" tank, even though yours looks well mantained. The fact that you have not found the dead fish tells me you had decayed fish carcases & most likely had an ammonia spike.

Tommy

[Homer_Simpson]

Krak256, I believe that you hit the nail on the head when you pointed to the fact that adding the crushed coral to the water to raise the PH ignited your fish deaths. Ammonia is only toxic at higher temps and PH levels. This link will give you an idea of how this works.
http://dataguru.org/misc/aquarium/AmmoniaTox.html

IMHO, you have a couple of things that may have contributed to your deaths. (1) raising of ph by adding crushed coral. Even if your ammonia level was high before, with a lower PH that would be irrelevant as the ammonia would have been in its non-toxic form. (2) PH shock. When fish adapt to a certain PH, they like that PH. There is a myth that you should not keep lower PH fish in higher PH and vica versa. I have kept lower PH fish in 8.5 PH "conistent" tanks and 8 years later, they were and are still alive, eventhough the plant was converted to a planted tank with c02 injection and the PH "gradually" dropped to 6.5. The key is consistency and small changes in pH. When you chucked coral in your tank, that probably cause a sudden spike in your PH and also caused the ammonia to take a toxic form.

Another question: When was the last time you changed your water and cleaned your filter. What kind of media are you using in your filter? If you are using floss, I would recommend, leaving 50% of the floss intact and only replacing 50% of the floss. While I would rinse the media in a container with the aquarium water with every change, I would not change any floss for a month. I have consistently found that if you change too much of your filter media and too soon, you will get ammonia spikes time and time again, regardless of whether you have a heavily planted tank or not.

[krak256]

one thing that happened before i added my new fish was my eheim 2213 breaking down. it took me 2 days before i got a new impeller and the filter starting again. do you think in that time, all my healthy bacteria died, resulting in the higher water readings?

[Blue Ridge Reef]

I guarantee some did. Did you have a powerhead or anything circulating tank water while it was out?

[fishscale]

Yeah, you've got a whole slew of reasons to choose from here. Probably some combination of them. Good catch on the pH

[BiscuitSlayer]

It sounds like the perfect storm hit your tank. Whereabouts of fish unknown (probably deceased), removing of crushed coral from tank, filter breaking down, and no water circulation. One long string of bad luck.

[MarkMc]

Originally Posted by krak256

one thing that happened before i added my new fish was my eheim 2213 breaking down. it took me 2 days before i got a new impeller and the filter starting again. do you think in that time, all my healthy bacteria died, resulting in the higher water readings?

I wonder how much of your nitryfying bacteria died with no water flow? The nitrogen fixing bacteria need oxygen. You might have lost all or most of your bacteria. I would say your tank had to do a recycle.

"Still, I think that when you replaced the carbon you somehow upset the bacteria that take care of ammonia and nitrite. Did you clean the filter media in any way that would kill off bacteria? Also possible, the coral might of had some type of contaminate in it that the fish reacted to."

This poster has hit the nail on the head. When you removed the carbon you removed a significant portion of your bacteria colony. Then the filter died? Looks like we found the reason for your fish die off. I feel for you. I once lost a whole tank of fish when my CO2 system malfunctioned many years ago.

[billr]

when i first started fish keeping i had all kinds of problems keeping small tetras and rasboras alive,cotinualy batteling with my ph.my tap is at 7.4 & i kept trying to get it to 6-6.5. what i found out is that a constant ph is more important than the ideal ph.i have malawi cichlids,rainbows,danios,corys,and others and they all do fine in the 7.4, so i believe that consitency is the key.just my 2 cents