If you put air stones in the tank, the pH will fluctuate upwards so much in a week, that it can be problematic. Check out MOLECULAR OXYGEN. There is info about it out there. I recommend putting a circulating pump with a timer to stir your nute tank every few hours. And you can use it when you mix the nutes.
Bigbud is organic stuff, I dont know about the sensi grow&bloom, so it will be problematic without hydrogen peroxide. Then again, you cant use it (H2O2) because of voodoo juice.
If you have low enough temperature where your tank is, a week might work.
How big weekly nutrient solution volume are we talking about?
When I grew organic, I used a 10 litre canister to mix up nute for the girls. If you need to mix tens or hundreds of litres, no canisters.