Hi Joseph! I'm Dr. Bridget. Thanks for your patience...I just logged in and saw your question still waiting to be answered.

70 gallons is equal to 264.97 liters. This is just my initial answer. If you need anything clarified, please reply and I will be more than happy to help until we get all of of your inquires resolved. Thanks!

If you are asking "I have 70 gallons of water and need to add 10ml/gallon of a 2nd solution how many liters of the 2nd solution do I need to add?" 70x10=700ml/1000=0.7 Liter.