Hi,
I think I can answer you in an exhaustive way, since I have been trying to make money from a faucet for a few years, but I have not yet succeeded.
First of all, it is necessary to understand where to take the profits and make the business sustainable.
The first thing that comes to mind is obviously to exploit the banner ads, but, to date, these really pay a pittance.
a-ads has an average cpm of $ 0.27, and is one of the best I've ever used, with thousands of views, the others are very close to $ 0.
The problem really isn't so much the ads platform you use, but the number of UNIQUE visits you get. Below 1000 daily visits, the earnings will always be tending to zero.
This is due to the auction mechanism with which advertising spaces work. If advertisers see that your site has low traffic, they will have no interest in placing their ads there, and therefore the price (and therefore your earnings) will remain low.
Also, many ad services don't allow you to put their banners on sites that have an Alexa Rank below a certain threshold, for example Mellow Ads (which I remember paid well) requires an Alexa Rank below 100K.
So the first step is to be able to have a good number of active users, but this means that at least in the first period (a month or so) the faucet will cost you more than it makes you earn.
So it all depends on whether you can set up the faucet so that users come to you, but without letting clean you out.
A good choice in my opinion is by limiting the amount that the faucet give for a single user during day, so If an user claim multiple time, you are sure he will not take more than X satoshi per day (this also prevent abuse).
You can do all other checks you think are useful to maintain the faucet sustainable.
If you have other question about you can pm me or inbox my mail, I'm happy to help.