hmm tuff to predict how that will turn out... june 7th is about 6 weeks away... In theory you could add another shrimp in a couple weeks and that will keep the ammonia going to keep the bacteria going. I would say as long as you have a good heater and your lights on a timer you should be ok. My only concern would be heat... does your house have AC
? if you do you should be ok if you leave the AC
on while you're away, otherwise you might want to do something to ensure the temp of the tank doesn't get too high if the temp out side rises while you're away.