Alcohol testing for probation

So my husband just got onto probation this month, as he went to jail in January for missing a court date that we didn’t know about. He stopped smoking weed the day he went into jail but another rule of his probation is no alcohol. He’s been having a hard time quitting due to him leaning on it from not smoking. He only drinks 1 Steele reserve a day and max would be 3 ( 3 being on the weekend) he’s promised me he will quit cold turkey today for his alcohol testing in 3 days and if he is negative for no alcohol in his system that he will wean himself off it. So my question is, do you think 3 days of drinking lots of water will be enough for him to show no alcohol in his system via pee test? I can’t even be mad that he’s drinking because he’s such a better person now then when we first met, he’s been off meth for 4 years, and we now have 2 beautiful kids together, he’s quit weed, and I feel like he’s accomplished so much since we been together. I just don’t want a downfall for him..