over stocked?

[bettamax]

recently in my 20g tank both my platies died (in the last week) and one of my younger danios (.75"to 1" size) is hanging out at the surface all the time .
i had just added 3 neons, a penguin tetra and a 1.75" pleco to the tank. the pleco is just temporary to clean up extra algae
before the platies died there were 4 danios, 1 penguin tetra, 4 neons, 1 harlequin, 1 SAE
ammonia is 1.2; ph is at 7.2; no nitrite or nitrite measurements at this time
am i over stocked? i also did two 25% water changes in 10 days .
i suspect i might be in a nitrite cycle

 

[semper fi]

how long has your tank been set up? have you tested your water? you should either invest in a water test kit or have your lfs check the water for you. post the results here and maybe we can give you a more acurate answer.

maggie

 

[cherrylt04]

I've seen simular problems, make sure your pumps are working correctly and your filters are clean. Sometime when fish come to the top of the tank like they need cleaner or better flowing water. hope this helps.

 

[bettamax]

since my initial post the danio has died and one of the neons, the neons weren't showing any signs of illness or stress,
i've moved the pleco back to his own tank
the others seem fine, i'll try changing the carbon filter, since it hasn't been changed in some time
the water is still testing 1.2 for ammonia and 7.2 for ph
i'll post other tests once done

 

[catman]

You should have zero ammonia in the water!!!

Any ammount of ammonia is deadly to fish.

Get a test kit that also checks nitrite and nitrate.

But it seems to me as if your tank has not been cycled.