Tip it straight into the top of the tank,i use about a whiskey glass full diluted in 500ltrs of water.You will get a lots of what looks like bubbles and you`ll say to yourself what have i done but beleive me it does work,what i do is wait until i get down to about 150ltrs of water in the tank left and then just fill up with water again,by doing this you`ll find you`ll get about 2000lts of water before you need to add another glass full.When you need to add more and it`s been cleaned out of the system you will get no more bubbles,although you get what looks like bubbles they evaporate almost straight away once on the glass.