Ive recently started a new tank it been running for about 3 weeks now. Its a 20 gallon long that i previously had about a year and a half ago but tore down when i moved. Prior to its current issues my son had taken the magnet stick on algae claener and stirred up all the soil, it was a dirted planted tank. This caused all my snails and shrimp to die but the fish were fine. Now that i have the tank set up again im having the same issues of snails and shrimp dying usually in a few days after being introduced. Ive got a new inert substrate in and new plants and though i used old filters and heaters if course i have new filter media which is lava rock and filter floss. The old filters have some hard mineral desposits on them from the previous tank and the drift would i have in the tank was also in the previous tank. Its some kind of amazonian drift wood. My water is medium to hard with high ph around 8 but i split it with distilled water. I add a comprehensive liquid fert called easy green and k2so4 for added potassium. My fear is that i have a concentration of copper in that water the tap water copper levels arent too high according to water department but i havent tested it myself. I have zero ammonia and sone nitrates. Currently stocked with ten neon tetras and a nerite snail that is always above the water line, question is, if i had a high concentration of copper in the tank before could my drift wood retain that copper as well as my filter and leech it into my water column. Any help would be appreciated.