Does Swamp cooler water need to be clean?

[FIGJAM]

I would be very wary of that system and vendor. Reading the website they deny there are any US standards for greywater devices, but this is clearly false. For starters, see ANSI/NSF-350, et seq.

That filter is nothing more than an expensive ($700!) mechanical crap trap. It uses matala media as a mechanical filter but does absolutely nothing for TDS, TSS, BOD, etc. These elements would need to be addressed to reuse the water on the playa for cooling.

I think you could do the same thing a lot cheaper and better with a couple of buckets, a paint filter sock, and a splash of bleach.

I was thinking the same thing, but a 5 gal. bucket with 2 gallons of charcoal topped with 2 gallons of sand, then add bleach.