Ben M
Formerly pest control
Once I've run out of the water conditioner that I'm using I'm going to start using seachem safe, as it's the cheapest one you can get. It comes as a powder though, so you have to mix it with a bit of water before adding to the tank. As long as you add water conditioner and make sure there isn't too much of a temp dip, then you won't have any problems with water changes with malawis.
cheers,
Ben
cheers,
Ben