G'day Leeanne,

Thanks for the question, I've just spoken to Jacqui at Biomagic and she said yes you can use the Heavy Duty Treatment for Waste Tanks in your household septic tank, she said to use 50mL per adult per week. They can email you a septic tank help sheet if you would like, just email sales@biomagic.com.au and they'll email it through to you.

G'day Rex,

The instructions on the back of the BioMagic Heavy Duty Treatment for Waste Tanks says that you should add approximately 50ml per 50l capacity with enough water to cover the base of the tank. If you were using it in a grey water tank, they suggest 10ml per 20L of grey water. If you were using it for a portable toilet or a small waste tank then they suggest 30ml to the flush tank with water and 30ml to waste tank with 1-2L of water. It's a biodegradable treatment so you shouldn't have any issues putting it in the garden and yes, it helps break down gasses.