Swordtails Dying

[Whiter84]

Hi,

I was hoping for some help to find out why I'm losing fish.

Tank 90l

Currently contains:
2 adult female koi swords
2 balloon Molly's
1 accidental Platy/swordtail hybrid
5 fry/small fish (not really sure they can still be classed as fry)
4 amano shrimp

I did have an addition 3 swords, black female, pineapple male and orange female, two died today one last week.

There were no signs of illness, no fungus, fin damage or spots, if anything their scales were slightly more defined, however were not in any way damaged or protuding.

Tank has been set up a year, and these were the fish I purchased shortly after, however I would expect them to live longer than this while healthy.

Took tank readings and all normal.
Ammonia 0ppm
Nitrate 0ppm
Nitrite 0ppm
Ph 7.4
Temp 26c

No fish have been added recently, no new plants, there are live plants but have been around quite some time.

I'm not sure if I can do anything to protect my other fish or just wait and see, or if they just happened to die of old age at the same time which seems unlikely.

Advice would be appreciated

 

[the_lock_man]

Nitrate at 0ppm isn't normal, unless your tank is stuffed absolutely full of plants, or you've just changed 100% of the water. If you are using the API kit to test, then this might well be a false zero result - the API kit is notorious for this.
 
How often do you change water, and by how much (percentage, roughly)?

 

[Whiter84]

Using the api kit, obviously judging colour number is not completely accurate, but was closer to 0 then the 0.5 colour.

Though I do have a lot of plants, so I wouldn't be surprised if it was lower than average.

I do a water change between 1 to 2 weeks roughly a quarter to a third of water dependant on how long since the last one. Last one was last Saturday after the 1st fish died.
That was supposed to read 5.0 not 0.5. So could be anywhere under 5.0

 

[WILDER]

Test your tap nitrate reading.
 
Did the fish have white edging around the scales?
 
Sorry for your losses.
R.I.P.

 

[Whiter84]

Tap water may be a very slight bit lighter in colour/lower, but that might just be me comparing colours. I was using the kit to cycle my coldwater tank so I know it will get other readings.

No whiteness, they looked healthy until the night before they died and then weren't as vibrant in colour and not very active. The only thing that was odd was the definition to their scales, hadn't been able to see their scales as clearly previously but they weren't raised so didn't think it was an issue.

 

[Whiter84]

I've attached a picture of the fish I've lost I took a few days before losing the first, not sure if anyone else can spot something I missed.

 

[WILDER]

Can't tell in the pics.
Do any fish have cotton wool on there mouths, or strands of cotton?
Do any fish have cotton wool patches on there bodies?

 

[Whiter84]

Nope, no whitness of any kind. As I said earlier other than increased scale definition that as far as I'm aware isn't a sign of anything except perhaps age they were perfectly heathy.

No growths
No whiteness on fins, gills, mouths or otherwise
No weight loss
Eating normally
Slight lethargy the night before they died.

As everything seems normal, water is fine, is a peaceful tank (no nipping) and there were no symptoms to treat, losing 3 in a week I'm not sure what I can do to prevent any more dying.

 

[WILDER]

Did the rest for long periods of time on the bottom of the tank?.
Did they lean to one side.?
What does it look like when your fish go to the toilet?
Do any fish go pale or darker in colour?