roots 707 growmix question. Help!!!!

[calstar]

I will be transplanting in about a week(they will have been in these 3 weeks and are ready) from 5 and 7 into 30gal smart pots; this is an outdoor grow. The 707 holds moisture so well I"m concerned I won't be able to water/feed them enough without keeping them too wet. Should I add something to the 707 to reduce the moisture holding aspect, therefore allowing more frequent water/nute feed cycles?

Question 2:

Should I add worm castings to the 707(either way, without changing the 707 or with the change)?

Thanks in advance for any knowledgeable advice.