Sanitizing Fresh Water Tanks - How to with NO gravity fill?

We have a similar setup and bought a water syphon from Amazon. I figure how much bleach is needed to sanitize my 100 gallon fresh water tank and mix the bleach with water in a bucket. The syphon end goes into the bucket and as the house runs, it takes the mixture from the bucket.

Another option is to measure the right amount of bleach and put it into your fresh water house. I would run some water into your tank first before adding bleach.