Bubble buckets and RDWC share many features- and flaws.
Getting the water temp in your bubble bucket below 66f for at least one hour a day while aerating the water vigorously will all but guarantee that beneficial aerobic bacteria will win the balance of power battle in the water.
I've seen my water temps climb to 75 in the daytime- but if it saw 66 anytime in the previous 24 hours, I knew it would be fine. Thus, I'm not as concerned about average RDWC temps as I am about getting a good cool in there at least once daily.
This will take more power than you might think, so try different options and take careful notes, keeping in mind that the thermometer itself will take a few minutes to register temperature changes.
Aerating vigorously includes splashing, flooming and waterfalls- airstones suck and should not be used for this purpose. I recommend a very small water pump for a single tub, something not bigger than 264gph, to create a waterfall; that is, let the water coming from the pump fall back from above the waterline. This agitates, mixes, churns and of course aerates the water far better than a bubbling rock.