Maybe you had something toxic on the waterfall system. I always let the water fall over the hydroton with no side efects. In fact also like the sound of the water flowing back into the reservoir, it's quite relaxing.
Maybe you had some salts build up on that lava rock and the water have disolved them, increasing the PPM and/or altering the pH.
I hope that all of your girls will recover quickly.
Maybe you had some salts build up on that lava rock and the water have disolved them, increasing the PPM and/or altering the pH.
I hope that all of your girls will recover quickly.