Very impressive and unobtrusive. I like the touch of the planks around the outside of the drum. Are you in an area where you have to deal with freezing conditions? If so, what do you do to prevent the freezing. I have a similar rig and am racking my brain trying to come up with something - I only have a few short months before I need to have something in place.

I don't know where the OP is located, so I don't know their climate. Thank you for adding your location, it helps knowing climates to answer questions.
Do you have a picture of what your using? Are you using vertical or horizontal nipples?
I have a 14 gallon drum and a 5 gallon bucket with horizontal nipples. I don't have problems with mold, algae or slime. I clean/rinse them out on occasion, haven't rinsed out my 14 gallon in 3 months, I just add fresh water to it.
Vertical nipples will freeze, even if they are installed directly into a bucket, with heat added. If you have PVC coming from the container with horizontal nipples screwed into the PVC they will freeze, even if the container is heated. The water will not heat up enough in the PVC. Horizontal nipples need to be screwed directly into a container and a heat source added so they don't freeze. I use a 250 watt stock tank deicer, it lays on the bottom of my 5 gallon bucket, with horizontal nipples. I won't use my 14 gallon in JAN or Feb, when it could freeze in NC.