There is another reason that I was saying to put quad outlets in:
A 12-2 has a bare copper ground cable, It would be used for a single 20 amp circuit. (YES it has three wires in it.)
You can share a ground and neutral across most circuits, but breaking the quad into two separate circuits on different phases will help. I mean this is new wiring being pulled, not like you have to tear out the drywall and pull the cable
In the event of a phase loss (elec company or generator) you will not lose everything in the tank area. Yes, it can also be used where you need 240v (Hopefully not to cook fish with though).
I have been a volunteer firefighter for 20+ years. I have been Treasurer of fire house for over 10. For a full time job I do computers/telecom. In my tenure on these, I have been on and also in charge of projects for renovation/new projects which has included the heavy-up of elec service and error-proofing critical utilities. (Not an error on the end users aspect, but on nature and other issues)
I have been in situations where the loss of a phase has caused problems and burned up pumps/chillers/compressors. While the loss of a phase will cause that segment to stop running in a normal home, at least some sections of the tank would continue to run. A quad wired on different phases would split the load and not take out everything. We do not use multi phase devices on a regular basis.
On a generator, in the future, the separate phases will even the load across the generator.
Just a thought/recommendation... Some people wonder why 1/2 their house goes out during a tree limb or brown out situation. Normally the entire circuit will go out. Personally I have lost 1 AC compressor and 1 dryer from inadequate phase protection. Yes this is based off multi-phase elec appliance. But just looking out for the future, espc with a generator involved.
Now I am not saying to go out and spend hundreds of dollars on phase protection, which would drop the entire load in the event of the loss of a single phase. I am just trying to future proof it some, since the walls are already open.
As the adage goes... Sometimes it is better to run a bigger pipe, in the event that you need the extra.... ok I used that wording on an aquarium discussion which actually greatly effects things. LOL...
Plus saying that you have '20A Double Pull GFI breaker' sounds so cool.