fish? I think Jaymi is onto something with her questions about what you are doing to make the water ready for partial weekly water changes. Do you put a treatment into it? If so, what are you treating for?
How many days do you let the water "season"? What temperature is the tank at? Do you have filtration and/or aeration? What would it be?
How long has the tank been set up? Has the nitrogen cycle (4-8 weeks) been completed? The number of fish may be ok for an established aquarium of a couple/three months, but not for a brand new one.
If the larger fish are dying and there is no sign of disease, they may be suffocating. This could be a household poison or something in the tank, but most likely your water has something in it or hasn't been given much chance to shed extra carbon dioxide and nitrogen and absorb oxygen.
I could be all wrong in this, but this sounds like what too often, sadly, happens with new aquariums. If you set up the tank again, all this would happen all over again, if you did things the way you have before.
Thank you for the info. Please consider the other questions others and I have asked. Please also read through that second section of Immediate Help. It may give you some insights into what has happened and what you need to do to make your fish more comfortable.
All the best!
uncle scott
[ Parent ]