RB and YANC only list the hydrated forms. With the exception of CaSO4 which includes the hemihydrate and dihydrate forms.
Perhaps include an option to select between these forms.
Perhaps include a note that the anhydrous forms can absorb water from the air which may change the weight and chemical amount.
Perhaps include pictures of each form to show which is which to help users determine this.
http://rotalabutterfly.com/forum/showthread.php/13-Hydrated-VS-Anhydrous-fertz
Some fertz are available in hydrated and non-hydrated forms.
E.g. calcium nitrate - Ca(NO3)2; Ca(NO3)2_4H2O magnesium nitrate - Mg(NO3)2; Mg(NO3)_6H2O magnesium sulfate - MgSO4; MgSO4*7H2O
RB and YANC only list the hydrated forms. With the exception of CaSO4 which includes the hemihydrate and dihydrate forms.
Perhaps include an option to select between these forms. Perhaps include a note that the anhydrous forms can absorb water from the air which may change the weight and chemical amount. Perhaps include pictures of each form to show which is which to help users determine this.