Dead Fish After Water Change

[Something Else]

Setup:55 Gal, 0 amonia/nitrite, ~60 ppm nitrite before water change, 74°F, PH 7.5 KH 40 GH 160. HOB Aquaclear 70 and 2 air stones for circulation. No CO2, planted, led light, using thrive all in one 2 times a week (ez green was put of stock), and Aquarium co op root tabs in substrate. AAA potassium sulfate ~10 ppm weekly 

tank mates: 8 black phantom tetra,6 rosy barbs, 7 zebra danio, 1 moor goldfish, 3 ivory snails .

Typical Schedule: Sunday remove 50% water (EI dosing plants), add seachem prime, sometimes add excel, then refill tank after a few hours I add potassium sulfate ~ 10 ppm 

Recent Schedule: last 2 months I have not been on schedule, and have been doing water changes ~ every 2 weeks instead, however I did them the same way as explained above. Last week I noticed nitrates accumulating, I missed the Sunday September 26 water change,  so I decided to do a water change as I typically do on Tuesday September 28, then planned to get back to my regular weekly changes. 

Problem: Today, did a water change as I usually do and came back to 4 dead fish and the rest are barely able to swim.

I don't think it's due to .....PH as the tap and tank were both ~7.5. The temp I added to the tank was slightly cooler and brought the temp down to about 69°F, but that's not unusual. I used prime de-chlorinator before adding fresh water. Fish didn't seem to show signs of stress before the water change...

About Me: I tend to feed heavier I feed once a day about 6 days a week. I let the flakes hit bottom for snails and bottoms feeders in all tanks. I own two 55 gals, one 20 Gal and three 10 gallons, I only had this problem with only this one tank, but my schedule and water change habits and fertilizer habits are the same for all tanks.

 

 

Any idea what happened? I honestly don't feel like I can keep up with this hobby anymore, every time I think I know what I'm doing I kill another batch of fish 😮‍💨

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Mmiller2001]

The 5 degree change so abruptly could be a cause. Do you prime the tank or the source water. Maybe they added extra chlorine at the source? Do you know the TDS of the tank and of your source water?

[Colu]

It's more than likely temperature shock or chorine as @Mmiller2001 suggested I would test your tap water for chorine you might have to double dose prime if they have increased the amount of chorine in your water try get the temperature of water closer to that of the tank during water changes  I aim for a 0.5 difference when doing water changes

Edited October 3, 2021 by Colu

[Something Else]

You know....  I think you just solved my days worth of fatigue..... It has never occurred to me that I need to add more prime if there is more chlorine but it makes total sense. Bottle says to add X ml to Y gallon and I never thought twice. .. or once LOL. 

I used to average the amount with the lid, and add a little extra incase im off, then recently took the 4L bottle and put it into an EasyGreen squirt bottle and using the 1ml pump as a measurement and dosing as per bottle instructions.

Today, there was a storm, and when there is a storm, my city loves to dump chlorine into our tap water.... 

 

Thanks for replies 

[lefty o]

i would probably opt for 20-25% water changes, 50% is a large amount, and if things are off a little, well anything could happen.

[Guppysnail]

On 10/3/2021 at 10:39 PM, Something Else said:

You know....  I think you just solved my days worth of fatigue..... It has never occurred to me that I need to add more prime if there is more chlorine but it makes total sense. Bottle says to add X ml to Y gallon and I never thought twice. .. or once LOL. 

I used to average the amount with the lid, and add a little extra incase im off, then recently took the 4L bottle and put it into an EasyGreen squirt bottle and using the 1ml pump as a measurement and dosing as per bottle instructions.

Today, there was a storm, and when there is a storm, my city loves to dump chlorine into our tap water.... 

 

Thanks for replies 

I am sorry for your loss. My water company randomly for whatever reason uses extra chlorine.  It usually comes out around 2 ppm but will jump to 4 from one day to the next. I have to test prior to water change to be certain how much prime to use ☹️

[Torrey]

On 10/3/2021 at 9:22 PM, Guppysnail said:

I am sorry for your loss. My water company randomly for whatever reason uses extra chlorine.  It usually comes out around 2 ppm but will jump to 4 from one day to the next. I have to test prior to water change to be certain how much prime to use ☹️

@Something Else most of our nation's infrastructure regarding water was built by the Civilian Corps during WWII. The Army Corp of Engineers explained to Congress that the predicted erosion of pipes would require the entire infrastructure to be replaced between the 70's (lower pH water areas) and no later than the 90's (pH above 7).

 

It didn't happen, and Flint is one of 60 water municipalities that has unsafe water. The solution in most municipalities has been to increase the use of chlorine and chloramine, according to daily water testing. 

I have walked back in after a water change to see fish gasping.

My quick response has been add another dose of Prime (I use an infant medicine syringe to measure), increase aeration, and *then* start testing and looking for what is wrong. 

Fish can handle one stress at a time, pretty well. 

 

Two or more stresses?

Depends on how resilient the individual fish is, and whether there are any invisible stresses you don't know about. 

 

If all the other tanks are okay, and you did the exact same maintenance with the exact same parameters and exact same temp change, there is something going on in this tank that is adding extra stress to your fish.

I would add aeration and Prime, and then start playing detective.