G'day Katherine,

It's recommended that you add 1 tablet with 3L of water for up to 20L holding tanks for 3 days, then add another tablet every 3 days.
Hope that helps!

G'day Tom,

I've just had a good look at these Tabs and can't see anywhere on the packaging that they indicate they are septic safe, they all just reference using them in a sewerage dump point. We'd suggest using something like Biomagic that we know is septic safe.

G'day Tim, 

I've just spoken to our caravan expert on the floor, and checked with the info provided on this product.

One of these tabs is enough for a 20L tank, and 20L equals approx 5 gallons, so it looks like one tab should be the right amount for your 5-gallon cassette toilet. 

G'day Hazel, 

As far as we can find Dometic don't make green tabs for rinsing. We have two rinse products in our range - the Thetford Aqua Rinse, and the Dometic Extra Care Flush Water Additive which you might want to have a look at instead. 

We have the tab capacity in the specs for these products Kerrie, the Dometic Toilet Care tabs all come as a pack of 16. Sorry if there is any confusion here.