I lose about 1-2 PSI a week on tubeless tyres, but on leaving the bike for a German holiday for 3 weeks last year it only lost a total of 3.5 PSI in that extended time.
One has to remember, that you can lose about .5 PSI just checking the pressure if you're not careful.
Yosi I went out and checked my rims and they say BEHR Germany, I also noted that there was a directional arrow on the rims, something I've never noted before. Obviously the rim is designed to rotate one way only, maybe that's why it didn't come with reverse?
Yesterday I changed my tyres back from TKC80's to Enduro 4's for winter, at the same time I had a good look at the inside of the rims and decided that when I change back again in about 16 weeks or so, I'll clean the innards with warm soapy water then dry them thoroughly before mounting the TKC 80 tyres.
Mick.