Harlequin Rasbras turning up dead

[Aremihc]

About 3 weeks ago I put 7 Harlequin Rasboras (Hets) into a 10 gallon tank that had been established for about 4 months and had a 2 year old Pleco living in it. Recently I've noticed a green water outbreak, and now my Hets are dieing. I had one dead 2 days ago, and another today. I've been checking water, and parameters are not bad. Nitrates a little high, but doing water changes for that. Could a nitrate spike to 50 be bad enough to do this? The remaining Hets, and even the ones who died have shown no lethargy, have been eating, have a red tinge and bright black markings.

Here are parameters this morning.


pH 6.5
Ammonia 0
Nitrite 0
Nitrate 30-50
Alkalinity 0
Hardness 7.5

 

[SpeedEuphoria]

is that your normal PH or has it dropped?

 

[Aremihc]

is that your normal PH or has it dropped?

Normal. it's the default of my tap water, and I haven't changed it since it stays steady.

 

[Devilishturtles]

That's tough. I had the same thing happen to me though mine lasted for a few years...then they just started dying...one by one.

Were they acting normal up to that point? Eating well? I doubt a nitrate spike could have killed them. Has your temp changed at all or does it fluctuate much between night and day?

 

[Aremihc]

That's tough. I had the same thing happen to me though mine lasted for a few years...then they just started dying...one by one.

Were they acting normal up to that point? Eating well? I doubt a nitrate spike could have killed them. Has your temp changed at all or does it fluctuate much between night and day?

North facing room, not much fluctuation as far as I know. I have neone right by the window and they're doing fine. Yeah, normal behavior before dieing, and no deaths since, so I'm hoping. Thanks for the replies.