jonathan

Can't say I've seen much difference, In my case, there is a place inline in the drain tube to pour in liquid so I use Algaecide in that but if you don't, use the drain pan tablets -- no idea which would work better though. It does work best as a preventative before you get buildup. My drain line is long with many twists and turns, lots of places ideal for buildup (I curse the builder for this!)

I live in Florida, I keep two things on hand for my HVAC drain line. First is condensate cleaner (less harmful to the plastic than bleach) which I use monthly and my backup is a Gallo Drain Gun. Even on my worst blockages, 2 shots of the drain gun cleared it out.