Seachem safe is an amazing product for all fish-keepers but it's not available everywhere, esp. outside the US.
Sodium thiosulfate is the active ingredient
in Seachem safe and can be purchase CHEAPLY anywhere. For example, in the UK, you can get 1 kg for under 10 lb.
Sodium Thiosulphate - 1kg: Amazon.co.uk: Pet Supplies
Here in the US, you can buy it cheaply at Kensfish. The directions to mix are here too:
The big difference is the removal of ammonia which SAFE does
and Sodium Thiosulfate does not. It's necessary if your water has chloramines and not chlorine. Sodium thisulfate changes chloramines into chlorine (which is neutralizes) and AMMONIA. So if your tap water has chloramines
(need to call your water company for this info), you also need to use a little bit of ammonia remover, such as Interpret, or API's ammo lock.
In the states, you can also buy a huge bucket of dechlorinator that is equivalent to Seachem for cheap:
It removes chlorine and ammonia just like Seachem but a whole lot cheaper.