They're actually the most stable and least fragile while they're these tiny things. I mean check them out.. they survived being thrown straight into saltwater... no filtration, only aerated. Have not fed for 3 days. No idea what ph is but ammonia would probably be around... they're most fragile when they convert to the freshwater living creatures. Many are lost in this transformation according to most reports. About 50% die in this process and have to be converted to freshwater slowly, not like the larvae which can be dumped straight into full salinity..