Batteries draining too fast after solar recharge

Those batteries are not deep cycle, they are a hybrid deep cycle/starting battery. Not the best choice for your application. A true deep cycle is needed.
At 70 AH each that gives a total of 140 AH and you need at least 140 watts of solar. Rule of thumb is 100 watts of solar for each 100 AH of storage.
If the controller or solar panels do not have a blocking diode the batteries can discharge back through the panels at night.