Prim ferm started but low yeast pitch count!

[goondog]

Hey all!
been brewing for a couple years on off and have a new question i couldnt find after searching.
Brewed a smash ipa yesterday OG 1.070 and pitched a 3month old imperial yeast packet. The LHBS guy said this is all i need for up to 1.080range. After some sleuthing i found that just like all liquid yeast there is probably a degradation in cell count of 200Bill for the packet.
After pitching I realized the calcs called for about 260Bill count.

Its bubbling away after 12 hours and wondering if i should just go ahead and add a half pack of dry yeast to make sure im covered?

Is there any harm after primary ferm started?

Should i just relax and...

 

[JimRausch]

She's bubbling, therefore she's fermenting and adding new yeast would be a waste. Whatever off-flavors you may have created by underpitching has been done, so yes, I would RDWHAHB. Besides, it's an IPA, and all those hops will mask any off-flavor.

 

[Rob2010SS]

As @JimRausch said, just let it go. If you added yeast now, it wouldn't do anything as any off flavors are going to be created in the early stages of fermentation. Plus, if you pitch more, it'd be another 12 hours at least before they'd even get started. Your fermentation would be very far along by that point. Just let it go and relax. You should be fine.