Mario, good test kits are essential to konw what is going on. for the last few years, I didnt test my water. everythign just looked good in an old established reef. on the new one, I am testing much more frequently cause I havent gotten a handle on it. I would suggest you get the proper test kits before venturing into the world of GFO and especially Vodka dosing. just a minute miscalculation, and you can crash your system fast considering your water volume. also, avoid some products for phosphate removal that contain aluminum. they can put that back into your system. also, if not maintaned and replaced frequently, the GFO can leech the phosphate right back into your system.
If you dont establish a precise baseline in all your tests, you cannot tell if what you are doing is helping or hindering. you should have exact PH, ammonia, Nitrite, Nitrate, phosphate, Calcium, alkalinity and Magnesium levels before you start to treat or dose any of them. that said, the CA, MAG and PHOSPHATE are more advanced. dont sweat them now.
Personally, i dont drink the vodka, but knew a girl who drank it like water.
Flow is all relative to what you are wanting to accomplish. if you want sps, shoot for 40-60X turnover with 10-15X of that thru your sump. the rest thru powerheads or a closed loop. if you are not doing sps (your lighting is a bit deficient for sps IMO) then you will be good with 20-30X.
Oh, and one last thing, while this group here is relatively good sized, we dont know it all and cannot always respond quickly. you may want to try and start reading the rest of the forums at RC. there are many more peeps online that can answer stuff alot faster and have a broader experience level than many of us. while I have been reef keeping for over 10 years, I am very old school and am just now looking at the new methods and technologies. Go ask questions in the big RC forums, and if you do a little searching, you will find they have been asked many many times before and there is a HUGE wealth of knowledge sitting out there. just gotta go get it.