I’ve just obtained some bulk quantities of Hagen Nutrafin Cycle, 236ml (8oz) bottles, Expiry Date 04/2006. I use it in the fish house all the time for maturing breeding tanks, and filters. TIP Pour a little Cycle on new filter media
A bargain at 5.00 GBP a bottle, a little less than RRP 7.49 GBP including p&p.
Nutrafin Cycle can be used to mature new aquaria and as a general filter booster.
Hagen claims that its bacterial cultures can remain viable for up to two years in unopened bottles, and for up to six months in opened bottles stored at room temperature.
Hagen also claims that it provides the highest bacterial dose on the market at around 500 billion live bacteria a time.
For maturing new tanks, you need to add 10ml per 35 l./8 gal. once a week during the first month and then switch to a regular maintenance dose.