This is my first post ever on riu. I love this place and it has helped me so much, so a very big THANK YOU to all!!! I've tried not to post anything, well because i am only on my second grow, and i'm definitely over paranoid. But hey better to be paranoid then not right. Well anyway its time to share some experiences and this one really hit home for me so i thought id give my two cents.
Hey man i had that same problem but i went as stealth as possible. I'm in college just about to finish up and just got the new apartment setting up to get a real job and all that shit. I live with my girl and i had my parents and her parents coming to visit and stay over night on consecutive weekends. I was shitting my self. Here's what i did.
First i want to apologize for the length of this post but i always feel that being as detailed as possible is the best way to go. Ok my grow is in a very small linen closet (2'x1.5'x8').
1. I took the door knob off and put on a locked one. Best decision i made as the girls mom asks for a tour of the apartment, which i end in the bedroom standing right next to the grow for some stupid reason and she just turns and tries to open the newly locked door and asks what's in there. I said "uhhhhh, I dunno I've never been in there. I think its a water heater or something."
2. I use two 120 mm pc fans (Scythe slipstream from newegg 110 cfm, and thermaltake from radioshack 78 cfm) wired up to an old 12v 3 amp gamecube power adapter for exhaust. very quiet for the cfm. They're rated at something around 40-50 db on the highest speed. I'd say you could compare their sound to a small floor fan on its lowest speed. I had trouble with my temps (90+) until i got my passive intake figured out (too many failed light trap attempts). Now i run at about 79*f which is pretty nice considering I'm running four 15 watt tube flouros and a 150w hps, two air pumps, an ultrasonic humidifier, and a couple water pumps to make my dwc's a little more aeroponic, as well as two light traps, one dividing the closet and the bedroom and one dividing the veg and flower chambers, all with just those two pc fans exhausting.
3. I then made a fan muffler/carbon filter out of a cardboard box lined with egg crate foam, an internal 180 degree bend for the air and no light to travel around and a standard carbon air filter cartridge over the outlet of the box. I sealed the box at all seams. My exhaust leads from the linen grow closet into another closet in another room. The whole thing looks like an untidy stack of boxes in the other closet but its actually my exhaust. The carbon filter is just from homdepot and cut to size, no smell at all. The muffler with the egg crate foam is a little funny. I researched them for awhile and then made my very simple design. It works very well to quiet the rushing air because the fans do not make any noise, the rushing air does. However its not so much quieted as it is masked. Meaning that i can still slightly hear the rush of air when i stand right next to it however it sounds like its coming from much farther away, as if the sound was in the ceiling or something and not coming from the muffler box.
4. As for the light, i just light proofed the door with some weather stripping on the inside lip of the moulding and light proofed my passive intake by cutting a hole through the drywall into the bedroom from the closet. However the holes are at different heights (the hole in the closet is 12 inches lower on the wall than the hole on the bedroom side). This created two nice 90 degree bends for the light to not get around. Since i have a negative pressurized cabin i do not have to worry about air leaks from using the stud space since all air will be getting sucked into the grow chamber and out through the powered exhaust
5. Also, with the door shut you can't hear anything, only barely a faint sound when your ear is pressed against the door. I don't have any sound insulation on the doors or walls either i just chose quiet equipment. That said i saw earlier in this thread that you were using an "elite" or "optima" or "pentair" air pump (theyre all basically the same air pump), most likely from petsmart, and probably chosen because it was the cheapest one there, i only know this because i did the same thing. That air pump is the loudest piece of shit thing i've ever heard. Louder than everything in the grow, even the water pumps and loud bubbling water. I took it back the very next day because i could hear it from the other room while it was running and got no sleep. The ones that i use now are linked to below. The first is from fusion, the fusion 400, and is the quietest, it also has a nice handy knob to adjust airflow. I bought it from that store in person. The second one i use is from tetra, the tetra whisper 10, it is almost as quiet but doesn't have the nice control knob, and it cost more and is less powerfull. I bought it from petsmart because the other store is too far away and i was in there returning the awful one. Both of the pumps can't be heard from outside the grow with the door closed and they are placed right next to the door on the floor of the grow closet.
Fusion 400:
http://www.thatpetplace.com/pet/group/4743/product.web
Tetra Whisper 10:
http://www.petsmart.com/product/index.jsp?productId=2753029
So thats it for what i did to hide everything from the parents. The visits when fine they never smelled a thing, heard a thing, suspected a thing. The only close call was the one with her mom wrenching at the door knob trying to get in. I swear mom's have a sick sense for these things because after she tried to open the grow closet she immediately left the bedroom and went straight for the closet in the other room that i exhaust into and opened it wide open. I was like "ARE YOU SERIOUS!" She didnt even look up at the exhaust muffler box, i was so worried she was going to smell the grow when she went for the exhaust but i stuck a couple dryer sheets in the muffler box the morning they were coming and the whole apartment smelled like a Laundromat. I think that was a true test of a stealth grow except for you know the police. I'm proud to say my grow stood the test of a mothers scrutiny. Here I was thinking they'll never look into these closets, thats what my few confidants for the grow were trying to tell me too. I'm really glad i went with my gut and stealthed everything up. I'd say do everything you can to hide it. Parents have no disgression when it comes to their kids and you should expect to have no privacy whether your 5, 10, 20, or 50 years old.
Sorry again for the the length, but me and detail are good friends. If you have any questions send me a message. I do not have any pics up or grow journals but am planning one after i harvest this current grow in a month. I'm changing from a traditional horizontal scrog technique to a vertical scrog technique to maximize the use of my small lights. Let me know if you want to see pics or anything i'll be glad to show/help.
Thank you again to RIU for all of your help, it has been greatly appreciated.
The only time the gay thing wouldn't work is if your parents weren't suprised if you told them you were gay.
So how did your parents take it? 
Does one's sexuality have any impact on ones sense of humor?
