Water Changes And Danios

[aryl]

I've been searching all over to see if anyone knows why danios in particular have issues with water changes. I change 50% of the water every week. I thought it was a coincidence when I lost a danio after a water change. I got three more and one died right after a change and another acted sick; staying at the surface like it needed oxygen. The sick one seemed to recover and in the midst of the next change it got sick again and later died. I change the water slowly to avoid stressing the fish. All of the other fish, including other danios, are fine.

In the other forum posts I've read in my searches I've found that danios tend to get sick after water changes, but there are no answers as to why those particular fish are more sensitive. Does anyone know anything about this specific issue?

 

[aryl]

To be clear, the surviving danios have never acted strangely or sick after a water change. The first one that died came from the same tank at the same shop at the same time as two that lived. The same is true of the two that died while the other lived. I have tetras and a pair of dwarf cichlids in the tank as well.

 

[Mr Bliss]

Potential causes that I can think of:

The new water is too warm or too cold?
Ammonia in the tap water?
Chlorine and/or chloramine in the tap water, and no dechlorinator added?
High chloramine content in tap water, dechlorinator is a brand that only deals with the chlorine (leaving the ammonia part in the water)?
Tap water has much higher pH than tank water?
Tap water is oxygen depleted, with high CO2 content? (the further you live from where the water comes from, the likelier this is)

Whatever the reason, I'd switch to smaller water changes (more frequently if needed) to alleviate the problem.

 

[aryl]

Thanks for your reply

I figure that a big water change will bring about... well.. a big change. I believe one died after a 10% change, but your point about smaller changes is well taken. My question is more along the lines of why it has such a big effect on danios as opposed to my tetras or cichlids.

My remaining danio population doesn't have issues. Now, I just want to know why those fish in particular are sensitive even though they're known to be a hardy lot. I did a google search and found that a few other people had similar issues with danios in particular and not the other fish in the community. The answers are all along the lines of what the general issues are with water changes, but not with danios specifically.

 

[Ficious]

i agree with what was said above. i think your water must have some combo of water quality and chemicals that it throw them off in particular. i bought all of my danios together and have had them for 2 years now, many water changes and move into another tank.




i would recomend you do smaller, more frequent water changes