Blow Off Tubing

So I pitched yesterday afternoon around 1 pm WYeast 1098 Smack Pack which ballooned nicely into OG 1.052 wort. The wort was on the warm side when I pitched upper 70s, but with a wet towel, adding water and running a fan I got the wort cooled to upper 60s in about 5 hours and has since held around 68 in the basement. It was starting a nice ferment last night around midnight, now this morning the blow off tubing is a highway of krausen foam and hop bits into the sanitized water I guess this why we use blow off tubing.....question is do I need to be changing the sanitized water or just wait until the fermentation orgy has slowed and then change it? I'm just concerned with any possible route for infection and don't want any nasties working their way in there.

Wait until it slows down, and stops discharging more solids into the blow-off tube, then install an airlock and try to clean up the mess. There's no point in changing the water as the CO2 generated by the fermentation is going to keep any nasties away from the beer.

-a.