Wiped out my fish in 1 water change...

I agree with Reedfish i think the problem is in the water. Sometimes months go by without any hassles or deaths and then that one day comes where everything goes bad - to much of something in the water that day. i can tell you one thing barbs are very sensitive to these changes.

F

 

So I spoke to our experts in the USA to confirm what I am thinking.... if the pH is above 7.6, the ammonia will quickly go from the NH4+ ion form, which is not toxic, to the NH3 gas form which is very toxic.

 

Water test: GH 7* dH
KH 6* dH
pH 8.0
NItrite <0.3 mg/l
CO2 levels fall within the recommended range.

 

Eish,I just love TASA members.
Why don't somebody summarise all the symptoms and possible causes and the we can tick them off as we eliminate them?

Temperature?
Maybe,but if the heater is big enough,how long will it take to raise the water from 18 - 22 degrees?

Chlorine/Chloramine poisoning?
Chlorine dissipates quick enough with vigorous aeration but Chloramine sticks around for days.

Ammonia/Ammonium poisoning?
My favourite,but it seems it will take a while to win the popular vote.

 

Before jumping to conclusions I need a bit more information. What was the tank temp and then the tap water temp! How soon afetr the clean of the filter and the water chnage did they start to die? Did thet all die at once and if not then over what period of time? How did you go about cleaning your cannister? Why dod you do a 40% water change? Rather do smaller changes on a more frequent basis. Leslie Ter Morshuisen, Grahamstown, suggest we should look at 10% daily!
When I clean out my cannister I usually just rinse out the bio balls to get the muck off. I never do a clean by using tap water. Want to save the bacteria. Will rinse out the sponges. I always add in Organic Aqua B-Bac when starting up again.
Please describe to me exactly what it is you did and don't leave out any of the details. Scotty

 

@Reedfish I did everything with the hosepipe, the filter and the refill. Nothing unusual as far as I know. Thats why I was so surprised because I did exactly what I have been doing for a year and all of a sudden it didn't work. From now on I will pre-treat the water and get it up to temp before it goes into the tank.

@scotty The tank was at around 22*C and dropped to 18*C after filling it with tap water (not sure what temp it was). They were all dead within 5 hours except one which is still alive. I rinsed out the filter media with a hosepipe. I did a 40% water change because I missed last week and it was looking a little yellow. I don't know what other details you want but I'm sure I have covered everything over this entire discussion.

 

Marco, clowns are from Thailand buddy and not South America. They do pretty well with Malawi's.

 

The one thing that really bothers me is you say you skipped a week and your water was looking a little yellow! Listening to comments made I would say, this based on the locals comments on the water from the tap, that you possibly had a chlorine problem which resulted in gills being badly burnt thus not allowing breathing. The rest of the comments re ammonia/nitrites etc are unfounded as these need some time to develop.
Only ever rinse your bio-balls in the tank water. I do 20% water changes irrespective of whether or not I did water changes weekly. I am a firm believer in doing smaller yet more frequent changes rather than a big one. 40% is to me an absolute NO!
Short of some form of chemical getting into the water I do not believe the temp drop had any affect at all on the fish.
What filtration do you have on the tank? 35 fish is hardly anything. With a tank of 600l I would suggest you look at around 3000l/hr filtration. Do youself a favour and try and get yourself a HAILEA HL-BT 1000 internal filter for the tank. Brilliant at polishing the water. I remove the charcoal box and put in a bigger piece of sponge. They need weekly cleaning as they clean extremely well.

 

Eheim 2250 classic is what I have Internal External Filters - Eheim Canister Filter - Eheim Classic 2250 Canister Filter - Guppy’s Aquarium Products Online - Eheim Classic 2250 Canister Filter

 

Just to stoke the fire a bit - what about Osmotic shock? If the tank had not had a WC for 14 days and then the 40% WC. The fish went from one water condition to a totally different water condition. I have never kept Malawis but I do know that that sort of change wouldnt be good for my threadfins.

 

@EnvironmentalBro, I'm really sorry for your loss. Much effort is going into finding the single cause of your fish's demise but tbh I think you experienced a perfect storm of variables which offed your fish. Main thing is that you are now armed with knowledge and experience. Cant really classify yourself as a novice anymore can ya? Best of luck with your fishkeeping future matey

@Marco, not every cool fish comes from discus land hey hehe

@scotty, it irks me when people think clown loaches do fine with Malawis, I assure you they do not! They might survive in those conditions but they wont thank you for it. They really should be kept in soft, warm water. It's for this reason some folks keep them with discus though I shudder at the thought. Its strange that people never put malawis with discus or vice versa but clown loaches are somehow a common denominator.

 

Hi,

I have too many large tanks to first heat the water and have also learned that a water change and similtaneous filter clean do NOT go hand in hand!
When not having done a water change for a while (for example being on leave) I have found comfort in emptying about a third of the tank, remembering to lower the heater to remain in the water, then replace the water in three stages over a week end and only clean the filter a week or so later. In this way the change is not too dramatic and allows some time to adapt. If I know I will not be able to do the necessary water changes, I also do a prior large change as late as possible so the water can remain "clean" for longer.
I never add anti-chlorine as I have previously lost a lot of fish without understanding the reason. On the other hand, I have a large air pump and push plenty of air through the water, which I have read removes the chlorine as well.
Some fish, like Deacons, Parrots and Silver Dollars are more prone to the change of the water temperature and replacing the removed water in smaller portions may be a good idea.
Now my fish appear healthy and "live"!
However, what worries me, maybe unnecessarily, is that my Pacu's only seem to eat when I move away from the tank, by which time the Malawis have climbed into the pellets/bits. I know they do eat as they have grown and see them eating off the bottom. Feeding leaves from time to time also helps. But, this has nothing to do with the water changes.

 

Hi guys,

Yes @scotty, Acknowledged already. Borneo/Indonesia to be more specific. . . My mistake. They should relocate to the amazon though. . . All nice fish live there.
@jedigenie already expressed keeping them with Malawis though. Thats just an unsane notion!

Can we now put this thread to bed as it has already started going south before. To be honest @EnvironmentalBro, at this point the cause if your problem is mere speculation. Learn from it and do things differently.

Just a footnote with regards to some comments.

When I get a new fish I place it a bucket and drip water from its intended tank to the bucket. This stabilise things over a period of time for the fish, and get him adjusted to temp, ph, hardness etc of his intended home.
If I now do a 40% wc on a 600 lit tank, with tap water running at approx 800lit per hour, it means it takes +- 20min for the water to fill up the tank again. Enough time for fish to adjust to the slight ph shift, the temp and hardness difference. If not, we will have dying fish when dripping them in also.

If chloramine killed the fish, they would all be dead, as the chloramine is still going to be present in the tank, we know no charcoal was used, and no dechlor was added. Chloramine wont just disappear.

So let us please now conclude, either chlorine or an unlikely but possible ammonia/nitrite issue killed the fish.
Suffice to say EnvironmentalBro will do things differently in future.

Rgds

Marco

 

@Marco Thanks for the advice! The effort to pre-treat the water in a water change exceeds the consequence of doing it the quick and easy way, trust me... Hopefully this thread has shown some people that its not worth being lazy!

Happy Fishkeeping TASA!

 

Doing a water change after 2 weeks is not being lazy. Not pre-heating your water is also not being lazy. The only time I have ever done a large water change, 50%, was when I had a sudden huge Nitrate spike. Did not have a single fish die from the water change!!
I did ask some questions, not all were answered. I agree people speculate, based on their knowledge, what might have gone wrong. The reason why I asked for some information before giving a comment on what might have been.
My suggestion to all is when something like this happens, hopefully it doesn't, one should immediately take a water sample that can be checked for possible problems. This will give a sound basis from which to try and figure out what went wrong. Without this it is pure speculation.

 

@scotty Well said. I am much more vigilant with my water tests, WC and general tank maintenance since this tragedy. Sometimes we have to learn the hard way unfortunately...

 

hi guys for me as a newbie this is all horrifying news to think one could loose your fish all at once is there a place or someone that can explain the steps how to do a water change and when ,also the bacteria and stuff to put back in when you done and also how and when to clean your external filter i put alot of money into this hobby (and so did all of us)i dont want to loose all at once .whats tests should be done in the tank , i only have a ph test .

 

@HAPPYBOY not that my word means much but here is my 2c worth :
1) do regular 10-20% water changes(not few and far between big water changes)
2) rinse your filter media in water from your tank;
3) buy a test kit and see what your tap water is like if necessary treat the water before adding it to your tank

so far so good the only time we have lost a lot of fish has been because of one of two reasons added a sick fish(unknowingly) should have quarantined it
a big 40% water change