Right now I have half of a divided 29 gallon tank to use for this purpose, and no place indoors for using a 5 gallon bucket. If I could raise them outside in the heat, I could use buckets, but I understand that maybe that is not best. The sediment on the bottom is green, so am thinking it is phyto. I am harvesting 2 gallons of rotifers every day out of the 8 gallons of water, stirring it first so as to remove some of the detritus each time. I have 3 rigid airline tubes bubbling at the bottom. I have been stirring it several times a day to get the phyto back in suspension. I guess a small powerhead is out of the question? Thanks for the feedback!