People head to Vegas Pool Parties to let loose and party in the desert you might want to think twice before paying $12 for that second vodka and Redbull.

According to Jon Taffer, the host of Spike TV’s “Bar Rescue”, who has owned more than 600 bars and clubs during his career. Whoever has the alcohol is in control, and the person that is serving the drinks in Vegas may be ripping you off. He crisscrosses the country, helping to turn struggling bars back into booming businesses. In an interview with “20/20,” Taffer said the sad truth is that some bars mess with everybody, not just the rowdy drunks.

Bartenders have tricks they use to cheat customers, Taffer said, from pouring less than the full amount of liquor you were charged for to watering down drinks and even secretly giving you a cheaper brand than you ordered.

So what makes you an easy target?

Some bartenders will apply one of the below techniques if you do a number of things when ordering from one of the busy pool party bartender:

waving your hands in the air

screaming the bartenders name

having an attitude when your not served next, or as soon as you walk up to the bar.

Cutting in front of others

not having your money ready

not knowing what you want, not knowing what your friends want.

Splitting the check on different credit cards,

telling the bartender how you want your drink

telling the bartender to “hook you up”

ordering a “Strong Island” or an “Adios,

stiffing the bartender

saying you can’t taste the alcohol

complaining to the bartender about how much drinks cost.

It can come down to what and how you order. Most people have trouble telling the difference between top-shelf vodka and the cheap stuff, Taffer said, so bartenders might try to charge you for the Grey Goose you wanted, but pour you a glass of something more like Nikolai.

“If you come and say ‘Let me have a Johnnie Walker Black on the rocks,’ I’m not going to mess with that. I’m giving you Johnnie Walker Black,” he said. “If you come up to me and say ‘Let me have a Grey Goose and orange juice,’ that’s the ticket to pour you the cheapest vodka I’ve ever had.” Here are a few ways Taffer says bartenders can rip you off, and why you should re-think your order.

1. Swapping Good Booze for a Cheaper Brand or Even Water

Sometimes bartenders will pour cheap liquor into an empty premium bottle, Taffer said, or they’ll add water to a half-finished top-shelf brand.

“Either you’re getting diluted liquor or you’re getting a different brand altogether,” he said. “It’s the epitome of desperation. It’s stupidity.”

This can be the bartender doing it themselves or the owner instructing the bartender to do it; with the goal being to make more money on each drink.

“Let’s say drinks are $10 each, if 10 ounces of water is put into a bottle” Taffer said. “They just made $100 dollars in cash that night. Times that by working 20 days a month, and by the year, it becomes very profitable.” This turns into and extra 24,000 a month in cash for the bartender or bar owner.

2. Giving You the ‘Short Pour’ They use the appearance of more alcohol in the glass to short you on the amount of alcohol in each drink. In the heat of the summer and the ice melting so fast that the bartender might be adding water to the drink making the amount of alcohol in the cup look more. Crushed ice, meaning the ice that comes out of those large bins behind the bar, means less liquor, Taffer said, while cubed ice allows for more space for liquor and is a better deal. But a half jigger of booze poured over crushed ice appears to look like more booze than a full jigger poured over cubed ice, he said.

It’s called a “short pour,” Taffer said, because “I’m going to charge you for a full drink and give you about half a drink. … You won’t know it. I’m going to rip you off and you’re going to be happy the entire time.” 3. Giving You the ‘Long Pour’ Don’t be impressed if your bartender can pour a drink a foot away from the glass, Taffer said. He is just cheating you out of booze by creating an illusion. “This idea is holding the arm up high in an exaggerated pouring motion, you think you are getting special treatment, you are only getting a special show. No extra booze, maybe even less,” he said. “When you lift that arm, you create an illusion of quantity.” 4. Giving you the ‘Sneaky Pour’ When a bartender holds the bottle over your glass for a long time, he is obviously giving you something extra, right?

Wrong, says Taffer, but you’ll tip him as if he did.

“The truth is they hold their finger over the air hole on the spout, which reduces the flow to a trickle,” he said. “They hold the bottle instead of the glass so you can’t see how little is flowing out. Then they quickly add the mixer and plop in that straw.”

That little red straw is the key to fooling you into thinking that weak drink the bartender just gave you tastes strong because, Taffer said, unscrupulous bartenders will keep those straws in a glass of vodka hidden under the bar. “The bartender draws a swig out of that vodka and your first sip tastes strong,” he said. “You are convinced, even though the rest of the drink is weak.” What to Order at Vegas Pool Parties If you want to make sure that you don’t get ripped off when you are drinking at one of the Vegas Pool Parties then you should order a beer. Beer is the only thing that bartenders cannot mess with.

“Unfortunately bottled beer is your safest bet,” he said. “It’s prepackaged. It’s sealed. You see it opened in front of you.”

To read the full ABC article click here