Bent Fish!

[webber555]

I did a weekly water change this morning (about 12 hrs ago), however as I was in a hurry accidentally added a bucket of water without it being dechlorinated. I realised my error and dropped a few drops of dechlor into the tank less than 5 minutes later.

I've been out all day but have just noticed 2 of my zebra danios are bent - like they have broken backs. They otherwise seem fine - is it something to do with the water I added, or the fact that I stupidly syphoned out some water to rinse the filter after I had added fresh stuff... (oh dear I'm a doofus) Have I induced a mini cycle? I have another DIY bio filter that was not touched, this should have taken care of anything anyway, and my other fish (RTBS, Rosy Barbs) seem fine, so I am tending to think that the bent backs are from my water change method, or something else... any ideas?

 

[Colin_T]

It is possibly from the water change. The chlorine might have affected the Danios because they are always swimming around the top and might have been near the new water when it was poured in. The chlorine could have damaged their kidneys or liver and caused the body to bend. Alternatively the new water stressed the fish and caused something inside them to rupture and that has caused them to bend.
See how they look tomorrow and see if they are eating. Fish eating is usually a good sign.

 

[webber555]

well the zebras are still eating fine and the worst was swimming with small stops and starts last night because he was stuck bent, this morning he is swimming normally, though still a little bent...

This might have to be moved now, but next q-

there is a slight oily sheen on the water surface - from underneath you can see it in the light and all of the bubbles from the venturi stay undissolved and floating on the surface... this has happened a few times, and a water change seems to remove it, but it comes back after a day or so. any ideas?

 

[pippoodle]

what are your water stats

ammonia , nitrites and nitrates

what size is your tank and what sort of filters are you using

 

[Colin_T]

oily films are common in tanks without much surface turbulence. They are usually caused by lots of high protein foods (bloodworms, prawn, etc).

 

[electric yellow]

Do you have an air stone in the tank? You may find an air stone will help the aeration in the water and break the surface, thus not letting the tank form an oily film.