my start of vodka dosing and why

Before I get blasted, I just want to state that I've done what i can and have read every suggested reading log recommended by you all. I have a 100 gallon tank with 100lbs of live rock with a 20gal sump. asm g2 skimmer rated at 250 gallons. dual built in overflow and a split return on both ends. return pump is rated at 1400gph before lift. current stock is 36inch zebra eel, 3in green coris wrasse, 3 1/2 female maroon clown, 2 1/2 male maroon clown, medium rainbow bubble tip anemone, 8in green brittle starfish, skunk cleaner shrimp, and about 15 blue hermits and 30 different kinds of snails. my nitrates were an easy to keep up with 10ppm. i removed my dsb in the sump and now i cant keep my nitrates below 40ppm. if i do a water change of 30% they will drop to acceptable levels but after feeding the eel they jump right back up. i'm getting desperate and need to combat it another way so i will begin vodka dosing. i will post my progress and keep everyone updated.