Here is some pointers when changing salt mix. Take note of your tank parameter specially the alk
, mag and cal. Keep in mind about the "balancing act" of these 3 trace elements. Once your cal starts to go up it affects the alk
by going down. While the mag is like a mediator of the other the 2. Meaning if mag is low the other 2 will go hay wire.
Now if your current cal is already high and you just did a water change which has also a very high cal, guess what will happen to your alk
? I would presume your original alk
is already low when you have a very high cal in your tank. It will go down some more. As mentioned low alk
is a haven for brown algae.
Suggestion: Take parameter of new saltwater and if alk
is low adjust by adding baking soda prior to changing water.