I always do a full res change instead of topping up nutes. This is because the nutrients in the mix may not be taken up at the same ratio as the Nutes contain, so it can unbalance the mixture, so a full change is beneficial.
Why the massive increase in nutrients? Doubling the nutes is not a good idea IMO.
Only increase your nutes if/when the plants and pH/EC changes tell you that it is necessary.
My ladies are 34 days old and I am running at less than 1/3 recommended strength for this age (Greenleaf MecaCrop).