It's just a simple lab stirrer from Apera.
https://www.amazon.com/gp/product/B01F34Y7VK/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
Works really well mixing up any of the 3 part solution, even with the soda ash. That picture above was using one of the spare OXO containers that I use for dosing (~13" tall and no issues with creating that vortex there). Used that before I received the 2L glass beaker in the mail.
https://www.amazon.com/gp/product/B01F34Y7VK/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
Works really well mixing up any of the 3 part solution, even with the soda ash. That picture above was using one of the spare OXO containers that I use for dosing (~13" tall and no issues with creating that vortex there). Used that before I received the 2L glass beaker in the mail.