quote:

usually like Mayish and Augustish

^^^^^^^^^^^^
Hmmmm. I see you speak California. lol

The "-ish" suffix has nothing to do with California. It's just a simple way to append a word to denote an approximation. Much like a tilde before a number (~6 means "around six", as opposed to "exactly six"), though you can also use -ish with numbers (sixish also meaning "around six").

The point is, it's not like I mark it on the calendar to do on a specific appointed date.

It's just something I do twice a year in roughly late spring and late summer, whenever the mood strikes me.

Thank for the info, had old oil furnace replaced two years ago with new heat/air pump and was unaware of need for this maintenance.

Just finished cleaning the small holding tank and added white distilled vinegar and yes, there was a need for it. I will add every three months when filter is changed.
Thanks to the OP and everyone for the recommendations.

 
It is so dry here, the AC only produces condensate for 2-3 months of the year. During that time, I inject bleach into the drain line, through the vent pipe.