Many tanks run without a slimmer at all. Being without one for a few days shouldn’t cause any issue at all. Like @flyline said, a water change should take care of any nutrient build up due to the slimmer being offline.
my 60g cube made it 22 years without. Your tank will be fine for a few days/weeks/months without. You might have to increase the amount/frequency of water changes if it's more than a couple weeks, but I wouldn't lose much sleep over it.