I found a great guide off Reddit to follow if you want to know if the acid you ate was real. It comes from WishIlivedintheNL.

Hi everyone, I've been stocking up for festival season and I've started to notice the usual large quantities of bunk/fake LSD. I've been at the game for a while and figured I could put together a kind of checklist for identifying if what you really bought is LSD!

Before I start all of this I'm gonna talk a little about test kits and LSD. There are two kits that can help you determine if you have LSD. The Marquis and Erlich reagent (THE erlich reagent is the commercially available LSD tester from Bunk police, easytest, NicU, etc.). I've never really used a marquis on LSD, I think you're pushing your luck. With regards to the Erlich I really do not trust it. I know that it triggers in the presence of an indole, and when you look at the chart it's clear LSD is the only drug that can fit on blotter; However, I've spoken with many people in the RC scene and it is very common for people to dilute their bunk drugs with a very easy to purchase indole. That means, that if someone is laying a sheet of bunk L all they have to do is grind up some melatonin and put it in their solution. If they do that their shit will trigger an Erlich test.

Step 1: Trust your source

This is kind of a bullshit one but from my experience you need to trust your guy. Always ask if he's taken some of the drugs he's about to sell you. If he has you need to ask him the following (this is why you need to trust he isn't bullshitting you on his response)

How long did the trip last (it should be between 10-14 hours)
Did you mouth feel numb when you took it. Real LSD should not numb your tongue at all! A few times I've had some it has numbed it a little but if you can't feel your tongue you've got bunk shit. (If anyone says they could "taste the acid" it was probably bunk as fuck)
How did you take the tab/dose? (If your guy says you HAVE to keep it in your mouth to trip then it's not L, I'll talk more about this later)
How many did you take? (FROM MY EXPERIENCE most LSD is layed/dosed out at around 50-60 micrograms, at that dosage your trip normally is)

1 dose-you feel a little funny and can drink/smoke as much as you want

2 dose-colors are vivid, things look closer or further than normal, some tracers

3 dose-Things look funny, mild pattern shifting, definitely know you're tripping hard.

If any of the questions to your dealer seem a little off or he responds with any of the negative responses I've listed above then you should tread carefully and maybe only buy a few hits to try it out first.

Step 2: Form factor

LSD comes in a couple different forms. The most common I've seen are blotter, liquid drops, or liquid dropped on some sort of candy. I'll handle each form factor one at a time.

Blotter: There are a few things that I look for when someone shows me blotter they believe to be LSD.

Size -Like I said above, the active dose for lsd is 50-150 micrograms. The active dose for a 25x-nbome is 600-1200 micrograms! The first thing I look for in blotter is size. I have NEVER seen a blotter of LSD that was larger than .5 cm by .5 cm, the tab should be small enough to fit on your pinky nail pretty comfortably. Anything larger than that should raise immediate questions.
Texture - The LSD on blotter I've gotten has a very non-specific feel to it. Because there is such a small amount of crystal in each paper your blotter should feel like normal paper. It should be pliable, soft, and bend how you would expect paper of its thickness to bend. Fake shit has such a higher dosage quantity, as a result of this when it is layed onto blotter the blotter will be very hard and rigid. If you have small tabs that are shiny/rigid/not bendable you probably have bunk shit. This is because the crystals are much more numerous and permeate throughout the whole paper
Taste- Some blotter/Acid solutions can be a little bitter. This means you can taste whatever is in your mouth but that's really it. If you have something like a 25x then your mouth will be unbelievably numb. You won't feel your tongue, cheek, lips, etc til the tabs have been out of your mouth for a while.

Liquid (I don't have a lot of experience with liquid, so bear with me)

Look for the same things I just mentioned, you should not feel your mouth going super numbed when you drop it. You should come up within 45-90 minutes and the trip should last 9-12 hours.

Candy

If possible look at the dose under black light. The areas with Dropped LSD should fluoresce.
With candy I have also gotten a DOx chemical. The only way to really tell is if you've been tripping for 15-18 hours you probably have this instead of LSD. One thing to remember is that like the 25x-nBOME's the dosage for DOC is 1-8mg. This means there will be a lot of chemical on the medium (this on is hard to tell besides taking some and feeling it out)

Step 2: So, you bought some and it made it through the above checklist now what?

At this point it is time to do some experimenting. This applies for all form factors.

Eat 1 tab and enjoy. Your trip should be awesome, pretty mellow, and last 9-12 hours. At this point you could find out you have DOC, or have been given super large doses.
If possible trip with a friend and have him swallow the blotter, candy, or liquid straight to his stomach. For example, if you had doses on altoids I would suggest having one friend keep it in his mouth and the other swallow it straight like a pill. If the person who swallowed it trips then you are able to rule out the 25i series.

Step 3: Make a moral decision.

If you have bunk shit you need to decide what you're going to do with it. From my experience most people will still buy it if you just describe it as NOT LSD. You can sell it for a normal price if you're upfront with people. Explain to them that this is a drug a lot like LSD but it isn't. Let them know not to take more than 2 doses for their own safety and go on your way.

Step 4: Enjoy

Hopefully you followed this guide and didn't get bunked, prepare to enjoy some amazing trips with one of the best drugs on the planet.