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AC Condensate slime question (ME)

Is the only thing I've found that works, but it has to be added regularly. I'm a partner in a bar and can speak greatly of the slime that forms in ice sink drains. It can completely clog a 3/4" i.d. tube in just a couple of weeks. It takes much, much longer to form in the condensate drains from the bar coolers. My guess is that just enough food (sugar) makes it into the ice sinks to let it grow explosively.

It's worst in summer when the cold water is surrounded by relatively warm air.

Have tried very hot (from a coffee maker) water to no avail.

I've added a tee with a filler inlet (not glued) to every A/C evap I maintain. A cup of bleech every couple months works wonders. In this area we tend to get a growth of a black-green slime on A/C evaps as well. I have to spray them regularly with bleach (to kill), brush with a big, soft BBQ brush, then flush with evap cleaner.

Probably half of the basements I visit in the summer have a trail of water leading from the furnace to the nearest floor drain. Every business with ceiling-mount units has water stains. Precious few above-grade units have an overflow pan (with the proper shut-down switch).

The absolute worst drains I've seen are done in 1/2" soft copper. Once clogged they're very difficult to clean. I pipe BOTH evaporater drains with 1" pvc, then drain these to a 1 1/2" dedicated (and vented) branch. Above grade I ALWAYS use an overflow pan and condenser float kill switch. I wire the switch through a DPDT relay to TWO neon lights in a prominent position. Yellow or green for OK; red for "clean me 'cause I'm not working." As a bonus, these little neon lights often make great nightlights.

Photo below by the little sink in my big closet.


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