I'm working with copepods for a school project and don't know much about them. I know that tap water will most likely kill them, so I'm not sure which type to use since deionized water will also probably kill them. I can't fit buying a bunch of spring water into my budget since I have to do 3 trials and I have 10 gallon tanks. Would water purification tablets (like aquatabs, aquamira, etc) harm the copepods? or would that make the tap water safe enough for them?