Salts CaSO4 1.0g, CaCl 0.6g plus a quarter tab campden. Yeast nutrient and whirlfloc at 10min.
Based on boiling 7.00 gallonsliters at 1.042 for 30 minutes, this will decrease your wort by 0.50 gallonsliters, bringing your after boil OG to 1.045. You wanted an OG of 1.050. It looks like it will be under.