Mysterious Mass Death

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Mysterious Mass Death

Post by mr_kgeorge » Sun Nov 04, 2018 6:06 pm

Tank: 4’x3’x3’
Filtration: 2 x Ehiem 2262
Medium: 2″ Poret 10 PPI
2″ Poret 20 PPI
2″ Poret 30 PPI
Biohome Maxi Ultimate
Chemi-pure Elite
Powerhead: EcoTech Marine VorTech MP40wQD – Set on Reef Crest Randon Mode
1 x giraffe catfish (Auchenoglanis occidentalis)
6 x Synodontis angelicus x eupterus hybrid
12 x Synodontis petricola
1:4 Red/pink Blood Dragon (Aulonocara sp.)
Heater: 4 x Cobalt Aquatics Neo-Therm 200 Watt Aquarium Heater – Set and maintained at 78
100 lbs CaribSea African Cichlid Mix Aquarium Substrate
100+ lbs of Lava Rocks

This tank has been set up for 2 months. Fish have been added past three weeks, not all at once. I perform a 25% water change every Friday. Water perimeters of the aquarium before water change is the following:
pH: 7.8
Ammonia: 0 PPM
Nitrate: 0 PPM
Nitrite: .5 PPM
My house has a filter (Pelican carbon series whole house water filter system) and softener (Pelican NaturSoft salt-free water softeners) system so I use filtered tap water for the water changes. The tap water is at 7.8 pH.

I noticed 24 hrs after every water change the female peacocks move to the surface of the tank and they look like they are gasping and struggling. After another 24 hrs they went back to normal behavior. Friday, 11.2.2018, I performed a 25% water change, Saturday morning all the fish were behaving normal. Saturday at 17:03, all the females were on the surface, I didn’t think anything of this and at 19:08 I found the 9 x S. petricola and 5 x blood dragons dead. I removed the remaining fish and tested the water. Everything is normal. Does anyone have any ideas or thoughts on what could be going on? I am stumped.

Thanks for your help and guidance in advance.

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Joined: Tue Feb 23, 2010 11:28 am
Location: Medina, Ohio

Re: Mysterious Mass Death

Post by deeda » Wed Nov 07, 2018 10:35 am

Welcome to the forum!!

How did you cycle the tank before adding livestock? You posted a reading for a nitrite level above zero and a nitrate level of zero so my guess is the tank isn't cycled yet.

Are you using any type of dechlorinator when you add new water to the tank? If so, post the brand and the dosage you are using.

Are you using softened water for this tank when you do water changes?

OCA member thru 11/2019

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Joined: Fri Oct 19, 2018 6:38 am

Re: Mysterious Mass Death

Post by bellamor » Wed Nov 07, 2018 11:07 pm

I am so sorry for your loss, but I am really curious about what type of procedure did you do before changing the water on the tank? It seems like something is off here since the fishes have started to misbehave.

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Joined: Wed Nov 08, 2017 4:00 pm
Location: Cincinnati, Ohio

Re: Mysterious Mass Death

Post by bdmminer » Thu Nov 08, 2018 7:50 am

I am sorry for your loss as well, As Deeda had pointed out and it came as a red flag to me as well that your nitrites are above zero and your nitrates are actually zero. That is an indication of a non-cycled aquarium, or an insufficient cycle.

On the topic of the filters, the carbon filter should get most if not all of the chlorine out of the water but you may want to still put in water conditioner to make sure all of the chlorine is gone. Also I have a whole house carbon filter and this is not your problem.

Now the Water Softener. This is most likely your issue, when you do a 25% water change you are also dropping the hardness level by 25% as well and that is most likely why your Dragon Bloods are gasping at the surface for ~24 hrs. During that time the substrate is trying to restabilize the hardness to a higher level by solubilizing the coral and shells in it, but never back to the level it was. So after 2 months the hardness will be a minor fraction of what it once was and since all of the fish you have need hard water to thrive this could have caused them to pass. Lets do a little math, if your tank lets say started at a conductivity (way to measure hardness) of 200 and you did weekly 25% water changes and each time your substrate was able to mitigate half of the hardness loss per week your hardness would be: 200, 175, 153, 134 ... this may not sound like much but it is really a lot of change.

So between adding soft water and possibly a insufficient cycle would be my best guesses to why you have lost all of those fish. The two solutions I have for you are:

First for the cycle either take some filter media (a sponge preferably) from another tank and squeeze it out in this tank, or if you do not have another tank ask your trusted local fish store if you could squish out one of their filters into a bag or bucket and bring that home and dump it in the tank this will instantly cycle your aquarium and fix that problem.

Second for the soft water, go to your fish store and purchase an african cichlid buffer that you add each time you do a water change this will help keep your hardness and Ph at a level that will make your cichlids happy.

Hope this helps and if you have any questions don't hesitate to ask. :)

PS: Check your heaters too, cobalt did have an issue once about chemicals leaching out off them and causing massive fish deaths. Not sure if there was a recall but something to look into.

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