Join Date: Jan 2008
There is no hard fast rule; some people use the bleach straight (like I do), at 2.5%, others use it 1:5 or 1:10 diluted.
At the end, you just want to leave your diffuser in the solution until the disc is white, and then you want to rinse well and put into some water with double the amount of dechlorinator. Afterward, you want to ensure there is no bleach smell as well.
An alternative method is to use Excel and to leave it on the disc for some time until the algae dies.