glad you posted- i think many here can relate to the idea of having a bottle of apap-containing pills at some point where they didn't know wtf to do w/ them (too bad not everyone researched it like you're doing ;P )
12.5mg* is a low-enough dose even for no/low tolerance (it'd be the equivalent of 8.2mg of oxycodone). if you have no tolerance, that was a smart place to start (i feel obligated to state the obvious and tell you how addictive these are

).
(*remember that you didn't actually take 12.5mg, that's what you started with. IIRC, hopefully someone can clarify, but i'm pretty sure an 'average' CWE's yield is in the ~80% range. this would vary with how you do the extraction. that clump of binders+apap in the coffee filter still has hydro in it, so you can do more washes than one and get your yields up ;P. just remember that when done "proper", you don't end up with enough water to keep *too* large a dosage of apap in the final product. repeatedly washing the same batch's gunk would result in larger final product, opening the door to problems *if* you fucked up and got too much apap in there. personally, i like running the final product through a fresh coffee filter just for peace of mind!)
kool aid wasn't enough for the taste? when i used to do this kind of thing, i'd do a bottle with like 20mg/oz, and i'd add like 50% more gatorade than recommended, never had a taste issue!<although that was typically oxy, can't say i recall much hydro>
heh, this is turning into a mini-cwe thread - sleeplessFS, definitely check that cwe thread if you haven't already, extremely in-depth
/edit: why are you doing 7 on the next wash? i understand just consuming 7 pill's worth, but are you planning to just do small batches each time you dose? ...actually i can see some benefits to that, even if they're unintended