I had same issue when first started using carbon filters. some things I live by swear by tips etc etc.. 1)first wrap ur flange with some elec tape or duct tape a few times. this will give some whe for them spiraled wire insid ethe flex to compress into when u clamp down. then put ur flex on and wrap the heck out where ur flex meets the flanges, then use two clamps for each connection-1 tightened down around flex, then another around the inch or so of duct tape that extended the flex onto ur flange. this will prevent any heat from causin the adhesive to give way completely. or other option is to use them padded neoprene duct clamps. them spiral wound wiring in the flex will press into it and make an easy quick tight fit. FYI THOUGH on them neoprene duct clamps. make sure and call place u order form and ask what brand or what company makes them. if they're the C.A.P or any other subpar brand name then DO NOT GET THOSE ONES! I bought over 100dollars worth them clamps only to find that the darn things the neoprene is not even actual quality neoprene AND the dam things nvere fit any flanges I tried em on what so ever. had to use big ol C-clamps to bring the clasps together on them enuff to even get the screws started and once I was able to get threads to bite on the screws, as soon as I gave the screw so much as one to 2 turns it would dent in the solid flange of whatever I was putten them on. the REAL DEAL neoprene clamps u truly want are the ones made by "FANTECH" I believe these are the same ones that are distributed by sunlight supply but ot sure. one for sure way to tell if the place u call to verify don't know answer is to ask them to look on the metal banding of the big clamps and ask if it has a "FK-some numbers" stamped into the metal just by the clasp where screws fasten into. if they got that then ur good to go. also find an online HVAC vendor. I found em cheaper by at least 25% or more form various HVAC vendors vs the hit an miss on what ones im getting form hydro shops. if ur connecting two flanges that are rigid like say a fan straight to filter flange then either do the same and wrap the filter or fan flange up wit some silicone tape is what I use, or duct tape etc to make as snug a fit as u possibly can and then when put together just use ur imagination wit whatever u have like duct tape silicone tape clamps etc. when comes to odor theres no such thing as overkill if security is concern IMHO. 2) I also take foil or duct tape and wrap the top 2-4 inches of the filter canister itself incase there is any settling of carbon this will more likely where it will be. and plus wit almost any fitler its the top half that gets spent first for me so I figure just wrap the top few inches then it forces the air to go thru the tighter packed areas down lower. also tape up all rivets/screws if any on filter. I use QUALITY SILICONE not latex caulk or cheapo wanan be silicone. don't skimp if its crucial again. I actually go overboard and I use all rigid duct work and wrap the male ends of all flanges/connections with wats called silicone tape til snug fit, then put together then foil/duct tape, then self tap screws or sheet metal screws, then more tape and over that I throw on a neoprene duct clamp. but as far as flex duct goes, I quit using it years agao accept for the inconvenient duct connections where got a small stretch of duct to go in wit a slight odd angle or something. but even then I still use max duct exclusively or at least thermoflo brand ducting. all other cheaper knockoffs tear easy and have lil pin holes in em, especially the strait foil duct. as far as flex duct goes the "max-duct" by canfan is hands down "Cadillac, but still if u got the know how and can get rigid ducting (solid metal ductwork) especially elbows u'd be better off as far as noise odor etc goes. jus my 2 cents. bt do not forget to tape all the (cant recall the tech term for them) the spots where the rigid elbow spin to make diff angles u need. basically the point im tryin to make is that ur dealing wit situation where things are under pressure and if u got any even if tiny gaps, leaks , holes etc, and if they in ur space then its gonna leak. now theres the issue of ur aircooled hoods if using any too. I got two yield master II's and after 2 years using them I really got frustrated wit smell leaks like you and was in my goin overkill goal here so I went and took some CLEAR high temp silicone and silicone any and all possible leaks in it. ESPECIASLLY where the grommet deal they use to run the power chord into the reflector to ur socket. no matter wat anyone tells me no one can convince me theres any of those out there that are completely air tight so silicone those too. jmo again. I even silicone my glass. I just disconnect duct at flange and reach in to change bulbs and clean that way. its a PITA but if its wat I gotta do to eliminate all smell air leaks then so be it. NOW, the biggest unforeseen culprit of odor leaks I found but not til very last was with the fans themselves. first I just wrapped em wit tape and called it good, but recently I took all my inline fans apart to clean the innards of them after years of use only to find that theres air goin in and out all over the place, screw holes chord grommets etc etc. so broke out silicone again
. there is an easier alternative granted ur setup[ wil allow it-simply put fan before your lights and blow thru and out for your AC hoods, but u still wanan seal ur fan good. I have yet to find a inline fan brand that is truly 100% air tight as they claim. also keep in mind that even a few pinholes in ducting so long as ur in mid to late flower on some stinky ladies, ur gonna smell it . and as far as the hwole stinkin up briefly after lights turn out.. always done that for me. but over the years of slowly unprading bigger and bigger ive finally got 100% smell fee. I also use a 10x40 canlite rated for 1500cfm but never trust ratings. the ones they give are under the conditions they set when testing and are deemed optimal etc.. but on that big azz filter I got 2 reducers going down to a 6inch fan on a variac turned down to just over 50% speed id say. so when they say "go overkill" on filter size. that don't mean get a filter rated like 100cfm more than ur fan. also remember the ratings they give are also for simple scrubbing, not single pass filtering. rule of thumb I swear by since finding harmony between fan filter sizing in life is I take the rated filter cfm and match a fan that ahs max cfm rating to a third of what the filters initial rating is. again, JMO and EXP. heck in the dead of winter i'll even down size to a 4inch canfan on that big ol 10x40 canlite. I last used the 8x40 wita 6inch fan but when I tried a 10x40 i'll never look back. and I may even upgrade to a 12inch filter later on next one I get just to go even more overkill. and then theres the luxury of noise suppression... if u willin to shell out 40 or so bux for a duct reducer then google up wats called a hump hose reducer. its a lot lowrr profile in height and ruber and vibration free etc... its wat they use for big ol diesel tractors air intakes etc... the 6x8 hump reducers I got cuz I blow into filter outside the grow due to filter size bein half the size my space (jk LOL) but naturally the whole metal on metal fan sittin ontop a canister wit a cvity in it tends to give off an awful drum whooshing sound to me and I put one these hump reducers in the mix and holy hell its like a dream , not to mention a tight snug fit on flanges. and they can even compress or stretch bein rubber ever so slightly if ur flanges don't match up sizes perfectly like so many flanges do like on hoods etc... jus make sure to get the actual clamps used for the humps cuz with the thickness of the rubber , the traditional wom type clamps rated for the 6 or 8 inch whatever u need wont fit, they just a hair too short. but I found 6.5" and 8.5" actual duct clamps for hella cheap on ebay and they work great or i'll take the neoprene off the garbage knockoff padded clamps I got and simply use the plain metal band and a wide clamp sorry for the ramble on but new here and coffee buzzin this morning so... hope someone benefits form it some anyway. good luck to ya.
