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Grow Tent OutGassing / Offgassing WARNING!!

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    Grow Tent OutGassing / Offgassing WARNING!!

    By now some at least reading this post will have at least heard of the Offgassing effect within grow tents being reported throughout the internet. This is a confirmed effect admitted to by at least one manufacturer of these tents, however it is obvious with the amount of problems occurring from various suppliers that more of these tents are affected than is being admitted to by manufacturers.

    If you are growing plants in one of these tents that is affected your plants will be displaying signs that you are chasing between over fertilising and nutrient deficiencies in what is a swing of a very small margin. Currently there is two threads at least displaying the signs of the Offgassing problem. The margin from one issue to the other can be very small indeed I have seen plain tap water with the PH set result in the plants displaying a N deficiency and then when .5 ml per litre of Canna Aqua Vega is added to the hydro solution or equivalent Terra product to the the same water for soil mixes within a day the plants display signs of over fertilisation and are burned. Even Superthrive at 25% strength caused the plants to burn.

    The obvious sign is the washing out or yellowing of the leafs, this has been seen in other pictures to get as bad as to make the leaf look almost white before turning brown. This can occur as early as the first few sets of leafs and has been seen to start within the time the plant reaches three sets of nodes. The main stalk will often not develop fully and along with the branches can be thin and fragile. Roots are also affected both in soil mixes and hydro set-ups and also in both set-ups when cutting down plants they are found to be hollow throughout as the pith refered to in the relating text of the plant cross section below is eroded.


    At the moment only one grow tent manufacturer as openly stated that they have a problem that being Hydrohut. The statement copied below is an open letter from the makers of Hydrohuts as basically a recall of there product.

    Open Letter from HydroHut to the public

    In the last several months, HydroHut has been made aware of and pursued a problem with some of its Huts causing a peculiar plant yellowing leading to plant whitening in certain, sensitive plants. While the issue did not arise in all plants, or all Huts, the existence of a problem was not conducive to our product’s mission.

    After several months of extensive testing, false positives and much interaction with the public regarding this matter, we have found an EPA approved compound that isn’t stable in our plastic and that causes extreme stress to certain sensitive plants. In the future, this compound will be removed during manufacture.

    Our focus has been directed at how to remove this compound from the plastic and to do so in a way that we could retroactively repair any HydroHut already in the field. As of February 2008, HydroHut will be repairing any affected HydroHuts at its facility. The exact process by which we repair the HydroHuts is extensive and proprietary and it will be carried out by a trainedstaff at our locations.

    We fully understand that this situation with our product has adversely affected many clients. For this reason, we are standing behind our product and are offering anyone who has been affected a way to have his/her HydroHut repaired free of charge.

    Any client, be they end user or store, can arrange to have his HydroHut shipped back to our Los Angeles facility for processing, free of charge. The HydroHut will then be shipped back to the client free of charge.

    All inquiries for HydroHut processing should be directed to with no exceptions.

    Please provide the following details in the email:

    1) Size/model of affected HydroHut

    2) Number of affected HydroHuts (only the HydroHut brand will beaccepted for processing)

    3) Address where the HydroHut can be picked up by UPS call tag (make sure someone is there to meet the UPS driver) Do not use a PO box as UPS will not pick up from a PO box

    4) A name to whom/which we can address the package going back to you, the client. (We will make a good faith attempt at getting your product back to you. If nobody is at the address to accept the package three times, the package will be sent back to Los Angeles. Any further attempts to get the package to the client will be paid for by client.)

    5) Please remove your HydroHut canvas or skin and box it up. Do not pack up your poles or hardware. Do not remove your frame. Do not attempt to ship us your frame or other items. We will only be call tagging the canvas in a box. You must provide that box and properly seal that box. We will send you a call tag for a specific weight based on the email you send to us with your HydroHut details. Again, we will only be taking back your canvas for processing; no other parts or hardware will be accepted. Leave your frame set up and intact.

    6) We will make every effort to process and reship your HydroHut canvas within two weeks. This is not a guarantee but it is our goal. Please note that ground shipments across the USA can take up to 8 days! Even if we process your HydroHut in only one day, there could still be 16 days of ground shipping, 8 days coming to us and 8 days going back. Be patient. Most clients will not have towait two weeks. Every attempt will be made to expedite each HydroHut.

    7) If a store has new HydroHut, still in its original box, the canvas can be re-boxed in a separate box, and the canvas will be returned to the store new and folded, ready to put back into the original box. Please keep your original box at your store including all poles, hardware, and instructions. Do not send us the entire unit.

    While this entire exercise may be time consuming, HydroHut is doing all that it can to rectify this problem as quickly as possible. We apologize to everyone for the difficulties incurred with our product, end-users and stores. Without a loyal standing of clients we would be nothing. It is our goal make this situation as right as we can. Thank you to everyone who has stuck with us through this difficult period.

    Evan Townsley
    Managing Director
    Follow up information provided by discussion with thanks
    HydroHuts encountered a toxic plastic issue related to some plants in their tents. The manufacturers have refused to come clean with what they did in China and asking them again for months led to no divulging of the truth. As we knew that the same machine manufactured for many brands, we assumed that other brands would come forth and admit a problem as we did, but that was not the case.

    Tracking down the culprit did take several months. The culprit has been sought before, 3 times to be exact but most of those years were pre-internet days and the word did not get passed around. Let us hope that our disaster and bad fortune will now lead to everyone knowing what to look for if these toxic plant symptoms ever reappear around the world.

    We at HydroHut have been well bashed for incurring this problem and unknowingly passing it on. It appeared in our product two years after we began selling our HydroHuts so definitely something was changed behind our backs, but we took responsibility.

    Our recall ran most of 2008 and included arranging credit for those clients affected who returned their HydroHut to the authorized store of purchase. The recall finished on December 31, 2008. We are now selling a new, non-toxic and much improved HydroHut.

    Following please find a letter with a link to the actual problem and how it was studied at 3 different points in the second half of the last century and several other links talking about the plasticizer/phthalate issue itself and those effects on plants and humans as they differ greatly.

    HydroHuts USA
    Suplemental information provided by Hydrohut


    Homebox claims its products are not affected by the Offgassing because they use a different plastic product to make their tents namely Polyethylene (PE) and claim that it is PVC based tents that are affected.

    Lately, we have had an increasing number of customers and retailers approaching us with questions and concerns about some problems they have heard of with grow boxes. Some were simple problems like the cover material becoming brittle with use or a strange smell to the boxes when they are new (due to outgasing); other problems ranged from weird, complex to some that were a bit frightening like plants yellowing and dying within the grow boxes. Everybody wanted to know if these things could happen with an Original Homebox as well. The answer is "No."
    How can we be so sure? Let me explain.
    Our Homeboxes were on the market for over 3 years before the first imitations appeared. In that time we have not received one single complaint. And, we can assure everyone, that all these problems will definitely not occur with any of our products which are of the highest quality.
    When starting the inventing process of the portable grow box we named Homebox, finding the perfect material needed for the cover was a huge issue for us. The demands were set fast:
    • Durable and tough but not too heavy
    • Lightproof
    • Reflecting inside
    Soon it was clear, that it had to be several materials, combined to one. Looking only at these perimeters, Polyvinyl chloride (PVC) seemed to be the best solution, followed by Polyurethane (PU), which has very similar properties. It is easy to laminate, tough and relatively cheap.
    But we also had clear demands concerning the protection of:
    • The users and consumers health
    • The environment
    Now, looking at these factors, both PVC and PU were instantly not a choice any more.
    We researched a lot, and after long time and many investments into trials and tests, we found the perfect combination for our Material.
    It consists of 3 layers:
    • on the outside we use webbed Polyamid (PA), for strength and durability and to make sowing possible
    • as a middle layer, we use black Polyethylene (PE) to guarantee that it is lightproof
    • the inner layer is white PE to ensure maximum reflection and perfect ability to clean
    Why did we choose to use PA and PE instead of PVC or PU? And why is that so important in reference to the occurring problems?
    To explain that, let us peek a bit into material science. What are the different characteristics of PVC, PU; PA and PE?
    Additional information supplied via discussion with thanks
    please take your time to look up the test report, which is posted on our website. is is also mentioned in the first post of the thread.
    this test repost is done by
    they are a world wide reputated neutral test lab.
    the report clearly says, that our material does not contain any measurable harmfull dyes, metals, nor phtalates. well, it contains 8mg/kg barium. BUT, the hardest limit (also stated in the report) is 1000mg/kg of Barium. so we are WAY BELOW the strongest restriction out there for household goods, or even children toys.

    What regulations and limits are we refering to:
    read our test report, and you also get the details of what SGS is referring to, when giving limits. or what they based their test criterias on.
    it is very scientific, but well, thats what is is: science. correlated to regulations from US and EU laws.
    for example: pg 4 of the report: the refer the german food laws: LFGB § 64 BVL B 82.02.2 and .4
    EU DIRECTIVE 2005/84/EC (Toys safety)
    page 5 metals: it refers to EN 71 PART 3 (migration of elements (metals) : toys safety): the limits are given there as well as our materials test results.

    i have to raise another issue: even if other tents DO NOT kill plants, they might harm the organisms being around it over long term. metals like lead, cadmium, etc, phtalates (softeners) might all migrate over long term. they then accumulate in plants (consumables??), and with that, in humans. so even though your box might not kill plants instantly, it might still poison you over the years. ever heard of lead poisoning, e.g.? worth investigating...
    There full explanation along with a link to their test report can be viewed at

    This claim that PE is better than PVC seems somewhat supported by information on the Greenpeace site for alternatives to PVC.

    Why PVC is bad news

    Globally, over 50% of PVC manufactured is used in construction, in products such as pipelines, wiring, siding, flooring and wallpaper. As a building material PVC is cheap, easy to install and easy to replace. PVC is replacing ‘traditional’ building materials such as wood, concrete and clay in many areas. Although it appears to be the ideal building material, PVC has high environmental and human health costs that its manufacturers fail to tell consumers.
    From its manufacture to its disposal, PVC emits toxic compounds. During the manufacture of the building block ingredients of PVC (such as vinyl chloride monomer) dioxin and other persistent pollutants are emitted into the air, water and land, which present both acute and chronic health hazards. During use, PVC products can leach toxic
    additives, for example flooring can release softeners called phthalates. When PVC reaches the end of its useful life, it can be either landfilled, where it leaches toxic additives or incinerated, again emitting dioxin and heavy metals. When PVC burns in accidental fires, hydrogen chloride gas and dioxin are formed.

    My opinion on this problem is that at present no grow tent can be trusted and it should not be our responsibility as the consumer to prove whether or not products we buy are safe. Given the issues that are widespread across more tent manufacturers than have so far admitted to it. It is now incumbent upon this industry to test and prove the safety of their own products using international standards set by the FDA, USDA, Canadian & EU governing bodies along with any other applicable. I would also recommend that all those selling these tents review whether they want to be involved in the distribution of a product that could lead to health risks in the population. At least the cigarette provision was done with most end users being aware they posed health risks and we have seen how many court cases have been raised once the risk to health was confirmed by external sources. I currently still have a tent that is affected by the Offgassing issue and I am considering the options along with costs to have it tested. I would be prepared to make samples of it available for independent third party testing.

    The bottom line is if you are using a grow tent and have never previously had a successful grow in the tent then you need to get rid of it as your first option in trying to recover your plants not your last.

    Revision I (always prepared to revise my opinion as new information is available)

    From discussions it is apparent that plastic product grow tents are not applicable to receive designated marking although Homebox at least recognises that this would not be a problem for them and would provide benefits to both the suppliers and the consumers. In the situation at the moment the best that can be aimed for is that plastic products meet the safety standards for childrens toys etc... under the EU Directive.

    EU DIRECTIVE 2005/84/EC (Toys safety)
    This can be viewed using this link 4:0040:01:EN:HTML

    Paste it into a new tab / window as its an EU government link and probably best not to have an active link back.

    Revision II
    A lo of good info provided which seems to support the assertion PVC is not a good material for use alongside plants.

    It is a distraction from the real issues to continue using the offgassing issue as a reason to bash Hydrohut in particular. From a consumer point of view yes there was an issue, yes an offer to solve the problem was made and yes it was carried through therefore there is no reason any institution like trading standards would consider they have acted in any way other than properly.

    The ongoing issue is with those brands who may discretely accept the issue on an individual basis, but are not publicly stating so. Also those still selling the same product as a quick search on a popular auction site would list hundreds for sale.

    I still think as someone without a degree in plastics or materials that since these issues are obviously known to the scientists who do develop these products that a product mark to signify materials do not off gas. Developed by the industry as a self regulatory standard would be a good idea. Even better if it was an EU and equivelant regulatory requirement.

    Cross Section Image

    This is an image of the hemp but with the genus similarity the same image is valid for cannabis IMHO.
    A thin cross-section cut from the stem of such a plant exhibits the characteristics in Fig. 7, in which A is the cuticle or outer bark, B is the woody part, and C the pith. The fibrous layer is between the two dark circles D, and a few groups of fibres in this layer are indicated by the letter E.
    Last edited by neuroherb; 01-15-2009, 14:35.

    The older ones are ok. The ones made in the last year or so are all fcked. People using the newer silver lined tents are happy for the most part.

    SUNHUT, HYDROHUT, and hell anything with a white lined inside id stay well away from.

    At least Hydrohut stood up and said they messed up. SUNHUT is still riding it out....Ill see them at the next vendor show in my SUNHUT TENT KILLS PLANTS tshirt!


      This has been a nasty problem over the last 8-9 months

      Big up to Evan at Hydro Hut who to this day stands firm behind his product, and is doing all he can to resolve the problem - and help his customers

      Hydro Hut has re-designed their tents - are using better and more reflective material (not plastic) ... and incorporated design changes that will make their tents better than before, and better than what is currently available from others in the market

      Hydro Hut's new line of tents will be available " very soon " ... keep checking the website .... and Hydro Hut customers are being made whole

      Under the circumstances - cant ask for more or better than that


        I got hit by the dreaded offgassing problem in my Hydro Hut execution chamber. Here's what they looked after 3 days.

        I didn't even bother to take photos after they problem progressed a bit because it was totally obvious. So, that totally wrecked my growing season last year. This time around I got myself a Secret Jardin/DR150 and it ROCKS!

        Those plants are in little 6 ounce cups and have since been transplanted into 2gal hempy buckets. They're doing great!
        Now growing White Widow, Sour Diesel, and Somango outdoors and organically!


          Under the circumstances - cant ask for more or better than that
          While I think Hydrohut have been the best I still find the tone of the letter above slightly arrogant especially in the description of what will be accepted back. As a company that has put a product with health issues into the market place I would expect a more contrite we are happy to deall with the issue attitude. Other than that I would agree so far they have at least stood up to be counted, but have in no way made any offering for customers consequential loss as a result of buying one of these products. Considering the health issues that have been related to flexible PVC and the plasticisers used then there is the potential risk to human health as well as the plants you grow in them. In the same way you can't see the plant killer gas affect your grow there is no idication how it travels around the property were the tent is located or how it thereafter affects the health of those residing there. If the links are followed then so far the biggest conern over flexible PVC and Offgassing is for the reproductive health of infants.

          I would agree the numbers and publicity has been very much over the past several months however the issue does go back further. My own tents are over 1 year old, are neither Hydrohut or Sunhut and I have spoken to people who have known of the issue existing but in much smaller numbers prior to HydroHuts open letter. There has been somewhat of an explosion in the past months but this could possibly attributed in some part to the explosion of cheap offers for these tents on an auction site. It wouldn't be a leap of reality to think that some previously identified bad batches have been released as no name brands in order to reduce the cost to the manufacturer.

          For the future I like the fact Homebox have had their equiment tested, but since there is a known problem I think the responsibility lies with them to ensure further versions are CE marked for Europe and will personally not consider another one until such standard programs are adhered to. also won't be quick to release any retailer or manufacturer from there product liability obligations which I give credit to Homebox for realising when they published all there testing information about the materials they use.


            I've had a homebox XL for a few years now and not had a problem with it. First grow when it was fresh turned out 485g, healthy plants not a problem. It's the white lined version.


              I think it's possible some people might be blaming homeboxes for their shitty grow techniques, either that or they're just getting a rep through association with growboxes in general.


                I'm sure there are some bad growers out there but this is well passed the "Carved in Stone, Guaranteed to be True," stage.

                FreezerBoy's Destroyer Diary-Completed...... FreezerBoy's Thunk Diary-Completed...... Beginners Links


                  Does anyone have experience with the HTG supply Grow Bright branded tent? I have I have one and I am beginning to become concerned for my health as well some newly transplanted babies. My fan is over kill so they don't seem to be exhibiting any problems as of yet (4 days), only a slight underfeeding during transplant, but who knows



                    Have you used the tent before for a full grow without issues?

                    If you have you are probably ok, but as there is no way to identify which tents have an issue just keep an eye on your plants as they will be affected first.


                    LOL at the attack I'm looking for rep, do a search and figure out how this topic came about.


                      I hope to god this gets a sticky, this thread is very good for the info on this problem. Neuro you will help a lot of peeps divert there thoughts into buying something different than these toxic huts! Hopefully they read this first though

                      Originally posted by Homegrow3r
                      I've had a homebox XL for a few years now and not had a problem with it. First grow when it was fresh turned out 485g, healthy plants not a problem. It's the white lined version.
                      This problem started occurring within a 6 month period from earlier this summer, not sure what was changed, but it sounds like there supplier changed some stuff to cheapen it up as they were just fine before this issue.
                      Last edited by MynameStitch; 11-11-2008, 09:04.
                      Overgrow Refugee Forever
                      The Complete Guide To Sick Plants, pH and Pest troubles! Updated! 7/15/2010
                      Stitch's Grow Pictures Thread

                      HeadyPete: Any "hydro guy" that advises you to spray anything, let alone a foul smelling, sticky oil on your buds should be bitchslapped right out of business.



                        No I have not completed a grow in this tent. I was wondering if any one else has had a definitive problem with those Grow Bright tents, and if they have I would like to get my plants out of there ASAP. So far they look good, recovering from the underfeed during transplant..... but who knows. I'll keep everyone posted on the HTG Grow Bright tents. O and by the way I purchased the tent around 10/25/08.



                          If as you say it has been fine up till now albeit you have had an underfeed issue you can defnitely attribute to your own grow ten you are probably still good to go. Personally I wouldn't use any but that is at least in part to my consumer views that we won't get the makers to take notice unless we enmass refuse to accept the stories given up till now and through hitting the bottom line through not purchasing them force the industry to clean up its own mess.

                          Also you have to take a successful grow in its relative terms. It is possible in my tent to grow and end product plant that will have approx 20g of dry bud however when the Seed Supplier claims 400g / m2 then it puts the grow into perspective as not being successful.

                          The following is in no way scientific because I have not recorded any details throughout a proper test however the first lot of pictures are from a re veg of Mirre plant by Karma Genetics which fought its way through the toxic tent to provide 7g of very fine bud with nice big calyxes. I can see from previous experience in these pics is that the stems are all very thin & the roots are poorly developed. The growth on it is all new from the little pop corn buds I left. I want a mother from this plant as it has proved its strength and quality and while it is ready to take the clones I have a few other things growing which means I am short on space currently.

                          The second lot of pics are of my current grow of Mandala Kalichakra clones growing in the exact same tent frame but using a mylar cover instead. These have been vegged for 3 weeks and are currently 10 days in flower. You can see how much more full the plants are the stalks well developed and roots that think there in a DWC system not NFT. They have never had a single yellow leaf nevermind droping several brown ones a day. I can assure you the last grow of the same strain looked even worse than what the Mirre re veg does at present.

                          Last edited by neuroherb; 11-11-2008, 19:17.


                            No attack meant guys, what I see is definite issues with the hydrohuts, but are you all sure that the homebox has problems, I don't buy it, and with the reports on their website it seems they have thoroughly investigated the possibility.



                              No worries, I would be tending to agree with Homebox I think they have done a fair bit to show how they are not affected and a lot of the information I have found originally comes from links they provide. I thought I had managed to put this across in the original post as I also included the link to greenpeaces pyramid on the dangers of plastics, but there is obviously some doubt by their customers or they would not have contacted them.

                              Personally the biggest worry IMHO is the literaly 100's of no name ones appearing on auctions as this is a way for manufacturers to dump products and cut losses.

                              With Homebox though they do seem agrieved with all the copies in an article they did with urbangarden.

                              Everest: Fair enough, hairy muff. Well can I ask you another candid question? Were you flattered when other ... how shall I say ... very, very similar products started hitting the market?

                              Denis: Flattered?

                              Everest: (Thumbs German dictionary) ... Wurden sie geschmeichelt?

                              Denis: (Swears in German) F***ing hell no I was not at all “flattered” by all the copies! It all started when a Spanish customer stopped buying from me and coincidentally started selling their own complete rip-off of my design. They even copied my logo. But it was Bangkok counterfeit quality – it wasn’t lightproof – it just didn’t do the job. I was really pissed off. But what could I do? More copycats came onto the market. It’s difficult to say which were just a copy and which had tried to do their own development. Inevitably, all these copies created some price pressure.

                              I take a close look at some of the Homeboxes on display around the office. One is even used to store tea and coffee in the kitchen! The quality is undeniable. The seams are hand-stitched and perhaps noticing me admiring the thick, strong canvas, double laminated with black poly-ethylene and white reflective plastic, Denis re-asserts how much time and effort he has put into ensuring the strictest manufacturing quality.....

                              Denis: At the end of the day it’s the quality of our product and our customer service that sets us apart. Some cheap copies use PVC to line their boxes – but this is heavy stuff and it also smells under those HID lights! Over time it becomes hard and brittle. We are also continually developing our products. This is a fast moving industry and we have to make sure that our Homeboxes are compatible with the latest systems.

                              I don't see them as being that far away from being able to certify their products as meeting CE standards so why ot go all the way and use it as a marketing feature. Personally I regret penny pinching on the tent purchase and paying for it across a years worth of dead grows.

                              Also in the article you get a hint at the numbers of tents being sold and it is defnitely a market worth a fair bit of cash. When I purchased mine the guy had 78 listed in his auction, was sold out and unregistered from the site within a day after delivery. If it was food related PVC products in the USA it would have to meet USDA, FDA & 3A standards however obviously Homebox is PE not PVC.