MM Platy behaving strange

[paulbrear]

We have had 2 female mickey mouse platies for 3 weeks now and they are both been really happy, out swimming around and feeding well.

We think one of them is pregnant but its the other one acting strange.
We noticed yesterday we hadnt seen it out swimming as much as usual,it was near the top of the tank behind the pump, not gasping for air or anything but just really still.

When feeding this morning it didnt come out and itusually does as soon as the lid goes up!

Just got home from work and checked on it (pregnant one out swimming hapily) and its in the bottom corner at the back between the greenery, again really still.

Any ideas???
Thank you

 

[fort384]

How long has the tank been established? What size is the tank?

Water parameters?

Ammonia
Nitrite
Nitrate
Temperature
pH

Tank mates?

Also, any sign of disease? Look at the fish closely for signs of illness.

 

[uh.oh...]

Yes, best way to help to determine the cause of misbehavior is with water parameters.

 

[paulbrear]

HI
We have had the tank set up since xmas, water was almost ready so was advised by Aquatics centre to add a couple of hardy fish to 'help' the water within our cycle. We bought 2 female mickey mouse platies, up until now they have been very happy.

My stepdad is bringing the test kit later so we can check the water parameters. If it was the water that was a problem wouldnt both fish be affected?

We have looked closely at the fish and cannot see any physical signs of illness.

 

[fort384]

Not necessarily. The water could be off, but one fish is better able to adjust or cope than the other. Water parameters are always the place to start when
Diagnosing almost any problem in your aquarium.

 

[i3k]

How often do you perform water changes? Is there a heater in the tank? What's the temperature?

I guess if it was me, I would just do a 50% water change.

 

[paulbrear]

Water changes are done if parameters are abnormal or when we clean the tank.
Temperature is 77-78.
Will perform a water change and then test the water.

 

[paulbrear]

We sadly we lost the platy.
We tested the water and we had a nitrite spike so been water changing to get the water to good levels.
But strangely the pregnant female is still happily swimming aorund and eating as normal, seemingly unaffected by the high nitrite levels - would this be anything to do with her pregnancy as I would have thought she would have been more susceptible to anything??

Thanks