Those concentrations all seem relatively harmless... they'd be exposed to more-or-less those levels in the wild. Watch for mould and bugs, but otherwise you should be ok. I'm not 100 % sure what Kalium is, but I'm thinking pottasium - in which case it's also normal. It certainly wouldn't be toxic to the spider. All of those elements are present in higher levels in the spider, and are required for normal biological function (actually, in pretty much the forms that are in the soil, I bet, except for the Nitrogen).Can I use soil with 5% Perlite?
The soil contains:
Nitrogen: 300mg/l
Phosphor: 105mg/l
Kalium: 249mg/l
Kalcium: 1600mg/l
Magnesium: 25 mg/l
I'm gonna guess German...Curious where are you from that you use the name Kalium?