It will work okay in such small buckets. It really doesn't take much to provide adequate air. But you may want to add buckets later.
That said, before I converted everything to venturi aerators, I used this line. This one is the best power to cost ration. Noisy, but a pumping fool.
I have the 1750gph version of this one but I have a large 80w CO2 laser. The smaller of this style should work well and you can adjust the airflow to what you need VIVOHOME Electromagnetic Commercial Air Pump, 20W-102W, 317/950/1110/1750 GPH, Outlets for Aquariums, Fish Tank and Hydroponic Systems https://smile.amazon.com/dp/B078H5MH75/ref=cm_sw_r_apan_glt_fabc_VSKHC4DXDKHXDSRSTVKM?_encoding=UTF8&psc=1
yeah I was running 8 DWC 5-gallon buckets, and i would manually take the bucket and empty it, after they start growing, they will be drinking most of the water and you'll have to add more than subtract anyway. You can change and fill the 2 buckets you'll be using faster then it would take for the pump to remove the water, depending on how far the nearest washroom/bathtub/backyard door is
something like this is all you need for a DWC system