Two male danios died from WC

[dslr.cow]

I cleaned my HOB filter in my tank and the water got really cloudy. Since it got so dirty, I decided to do a 1/2 WC.

Don't know if it was all the crud from filter or cold temp. of water ( I did a water test and all the parameters were normal.), but my two male danios started acting weirdly - swimming upside down, going to gravel and laying still for a while then swimming again; and died after around five minutes.

The two male danios are survived my a female and a month old offspring; two platys and a cory.

RIP

 

[seastaar88]

it could have very well been from stress due to cold water. a 50% w/c on a 10g is pretty large and adding 5g of cold water can bring the temp down quite a bit. when you do a w/c, make sure to use warm water. tropical fish are just that -- tropical and are sensitive to temperature changes. even though danios are hardy little guys, they get stressed out too.

 

[JNevaril]

I agree, the cold water will more than likley shock their systems way too much.

In the future, what may help you, is to have your water for your water changes ready a few days in advance.

Since you've got a 10 gal, it may not be too hard....a 10% change is 1 gallon of water, so you could have a gallon jug that has been treated with de-chlor (yes, the cholrine will evaporate, but the chloramine won't.....most tap water has this chemical in it...).

Let that jug sit for a few days...heck, get it ready after your water change....it will be room temperature when you are ready to add it to the tank, and it won't be such a shock to their little systems when you add it in.

Just a thought.

 

[dslr.cow]

Thanks. Yes, I do that, but since I needed more than 1 gal, I got new water, and I got cold water because I read somewhere that cold water is cleaner than hot water.
Lesson learned.