+1 on the magnetic stirrer. I use this and a 1 litre conical flask to mix my own Aquaforest dosing liquid (1/3 the price of the premix) and also to mix SW to add to the ATO of my QT when I am raising salinity for fish in quarantine. Considering I am now mixing up to 30 litres of dosing liquid at a time I couldn’t live without it.