Tomorrow I’m going to change my 500l South American tank to black water , I have decided to use roobios tea as it seems easy and cheap I’m hoping to boil up 10 litres of concentrate and poor into the rest of the tank , I plant to use 10 of the tea bags which is 110g of roobios I think should this achieve the mild to moderate tannins I want and is there a better way than the way I’m planning to do it