let your water from the tap "offgas" for a couple hours with a bubbler, then test the ph...
you don't want to change the ph more than .2 or so in a single dose/24 hours..
my system sat in the high 7's for over 8 months before the ph dropped, it now has to be bufferred, and all my plants did fine, with light dosing of maxicrop with iron (a quart lasted me over a year)
but i do understand the need to experiment.. i just picked up a couple bags of daphnia during my lunch break, three 5 gallon glass fish tanks for the daphnia, with five 5 gallon green water buckets to feed them.. trying to order some scuds today too.. lol