I raise my chicks as closely to a mother hen as possible. That includes no lights all night long, no constant heat on them, out on the dirt from just a couple days old, and no additives in their water.
I know that there are folks that won't raise chicks without all the ACV, probiotics and/or electrolytes added to their water, but the way I look at it is that while that stuff might be great temporarily for sick, stressed, or injured birds (even the back of the packages tell you that that's what it's for) they aren't intended for long-term use in healthy birds. They also tell you to have clean fresh water also available while using them. If a chick or chicken is healthy, that means that all of those electrolytes and probiotics in their systems are already in balance....why in the world would I want to give them anything that could throw that balance off?
We always want short cuts..it's just in our DNA. "If giving a bit of ACV in their water totally prevents worms, then I'd never have to worry about that or go through the worming process. I'd rarely have to scrub their waterer." See? But nothing we can stick in their water can make up for just those things which are so essential to good chicken management, and in fact can give us a false sense of security. We see it all the time on BYC - people posting that they found roundworms in their chicken's poop when it dropped a bomb on the sidewalk, and wondering how that can be when they make sure to give them ACV or DE. Fact is that that means there are unseen worms in feces out in the coop or run - if the vinegar is in the water then worms aren't even something they think about. Same with using DE for mites and lice....might be fine if it wasn't so doggone dangerous to use. It does kill soft bodied critters, but in the process that silica is getting into their lungs when they breathe it in and yours when you put it down for them. That doesn't mean we shouldn't be proactive with our care....it just means that proactive should be more than a bottle of Braggs and a packet of electrolytes. The only product I always, always kept on hand was Poultry Nutridrench. Chicks suffering from shipping stress got some, but I didn't put in their water for the entire batch to use unless the entire batch was having issues, and even then it was for a day or so with fresh water available as an alternative hydration source. Fortunately I only had that happen once, with an order of 15 Silkie chicks that didn't handle their shipping experience well. Those products can be lifesavers when they are needed. Too often they are used when they aren't needed.
I always see people citing their chickens as perfect examples of why this or that is so effective. Fact is, those birds may well have been just as healthy without all the additives, but since they've always used them there's no sure way to tell.
In the end it's entirely up to you.....you are there, I am not. You know your own setup and your own comfort zone far better than I do and if you decide that you really want to do this then by all means, go ahead and do so! What's right for you is your decision to make and certainly not mine. Each nickel has 2 sides, and I just wanted to flip the coin over. Best of luck to you and your new chicks!! You're in for such a wonderful adventure!!