Rather than straight bleach, I use the chlorine granules used in hot tubs, pools, etc. Just a teaspoon is all that is needed. I add it while I'm filling the tank, then run the entire tank full through the faucets and drain. Then fill the fresh water tank again and off i go (you can choose to do a second fill and drain with straight water if desired).
I did it to both my TT and clipper when I first bought them- haven't had to do them since. When I got the TT, it had the very stale, gross smell of a stagnant moldy tank - one cleaning and the water was as fresh as what comes out of my house faucet.
