Casualties after change of water purifier

[tongyang]

Have recently tried topping up my tank with water dispensed from my new tap filter/purifier and came home with a shock to discover almost all my fishes have perished. Only left with one large cardinal, oto and baby platy. The shrimps and plants are all fine. I've done the same with my previous filter without problem. Could be the UV purification that made the water unsafe for the fish. I'm traumatised with guilt now. Anyone encountered the same?

[coolgear101]

I always use the reliable brand such as seachem. But your case might not be the conditioner.

[stormhawk]

UV purification does nothing to the fish except to kill bacteria and algae spores passing through it. It is likely that something else is leaching out into the water from your new purifier system. Have you checked the output water to see if it is really in the state that the purifier system seller claims it to be? If the shrimps are fine, then it's not copper poisoning. Testing your output water from the purifier will be the best way to determine what went wrong.

[tongyang]

The purifier is supposed to make tap water drinkable and we've drinking from it without any prob. Didn't expect it to cause disaster to my tank. Did a more than 50% water change quickly. the surviving fishes are not well too. would think that BB is affected too.

[Urban Aquaria]

Check your pH levels... the new purifier could have converted the water to very alkaline (water purifiers always tout alkaline water as better for drinking), the swing in pH could have affected your weaker fishes.

As we all know, a higher percentage of ammonia in acidic water exists as harmless ammonium, but if the pH swings to alkaline too suddenly, the ammonium turns into harmful ammonia, and that will kill sensitive fauna.

[tongyang]

Thanks UA, what you've said ought to be it. As of now all remaining fishes have perished. didn't expect them to be able to pull through. The impact of topping up barely 5% of total capacity!

[Urban Aquaria]

Thanks UA, what you've said ought to be it. As of now all remaining fishes have perished. didn't expect them to be able to pull through. The impact of topping up barely 5% of total capacity!

Hmmm... 5% seems very little, the effect on existing tank pH shouldn't be that much in that case, even if the top-up water has high pH.

I think better check the purifier, it seems quite odd that the water it purifies can decimate all the fishes in your tank in such a short time with just a small top-up.

[bennyc]

I agree with Urban Aquariathat 5% seems little to have such drastic effect? Is there any other changes? Mind sharing what purifier you are using to prempt the rest of the community the danger.

[tongyang]

Ok, cause of death known: CO2 overdose. Left for work later today to discover it. Someone in the house meddled with the regulator. Yet to find out who and how. So false alarm on the purifier.