Can fish die quick from sickness or water conditions, without symptons before?

[Star_Rider]

well your water might be of some concern, it can be a source of lots of problems when coming from the tap depending on a few things. first you could have a ph level that is way off which is stressnig the fish. the food doesnt seem to be a problem but i would focus on using di or ro water as that is the best to put into a tank. you did not mention what was being used to filter that too may be a problem.

you do realize that ro/di has all of the minerals removed.will be a neutral pH 7.0 ..right?

this will cause some issues, as the water will have 0(zero) buffering capabilities and will likely result in a pH crash.

or you can use ro/di and add the proper buffers..

generally (unless you have real mineral issues) this is not a good idea.

get a kH/gH test kit to see where you are in these readings.
you may also look at Fe in the water as this has caused issues for some folks if there is too much Fe(iron) in the water

 

[vanpudin]

Thanks for the advise. I'm using a whisper power filter rated for 60 gallons. I realize that i probably need to upgrade eventually. At the same time though i've only had about 8 fish in their intill recently, the largest at almost 3''. I also have xtra air being pumped in the tank through an airstone.

 

[vanpudin]

Just bought AmQuel+, made by kordon. Is says it removes nitrate, nitrite, amonia, chlorine & chloramines. It can't hurt since my last test showed above normal levels on all i believe. Is it safe to use with my stress coat since it removes heavy metals from water? The AmQuel does not. Should i use a normal dose of each, 50-50 0r 60-40 or etc. for the amout of the two diff treatment?
Thanks for any advise.
soon i'll buy a test kit.