The standard (gold standard if you will) for our sodium hypochlorite strength that we mix with our GM6000 is 10%.
That being said, it can be quite difficult to locate bleach, pool chlorinating liquid, etc. at that strength. Most available bleaches carry a 8.5% strength at best and often down in the 5% range. You can sometimes find it in the 12% neighborhood but typically at a prohibitive cost.
After scouring the web for hours I've finally been able to locate the golden elixir, and right in my own
back yard. Walmart! And at a price you'd expect from Wally-World, currently under $3/gallon.
Not every Walmart carries the bleach so check out the link below and you can see if it's available at your local store:
So when it comes to figuring out the right mix for your GM6000, it's not rocket science.
In fact it's elementary my dear...uh...Technician.