DIY grow box....would like suggestions

I am planning on building a grow box big enough for two plants. I will be growing critical mass. I just finished with two and started flowering at 13 inches, they grew over 5 feet. Not enough room. My tent was only 3.5x3.5 feet 6.5Ft. tall. I will be topping and scrog so I shouldn’t need to worry about height. but the outside dimensions are a little concerning. 4x8 or mabey 5x8. I am going to try to build it so i can enter on all 4 sides so i can have easy access to the plants, tie them down. water proofing will be a challenge not sure what to do about that, I run RDWC and i have carpetted floors and don’t want them dammaged through misshaps. I want to be able to use and reuse it so mylar and something to fasten the mylar to. any suggestions would be appreciated.Buying a tent would be ok but there water resistant and I wouldn’t be able to enter from all 4 sides. Thanks in advance.

@sillyman…a cheapo way: 1"pvc pipe, tees and 90’s for a frame to hang the mylar.
easy to do, build to your needs. Could double over a plastic tarp for a floor covering. If you put 2" pvc around the edges, it would help keep water inside the tarp area.

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You could get the white plastic roll 10 mill’s thick for your floor and help light bounce back up. Just like @tanlover442 said with the pvc pipe and make curtains with panda film or Mylar

Thanks. I know you a person really doesn’t want to use wood because if it gets wet you get mold. If a very thin piece of wood 1/8’" painted and then a tarp stapled on bottom and the white plastic stapled on top do you think that would prevent mold from wood and be water proofed. the 2" plastic around edges, never thought of that but great suggestion.

Consider an affordable kids wading pool to contain water spills. Plenty of sizes to choose from.
Quick solution.


What happened that your plants stretched that much? 13” to 5 feet definitely isn’t normal. What did you have for lights?

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I’m new, need guidance on indoor and outdoor technique and equipment. Can someone help send me in the right direction…

I don’t believe it was abnormal. I just had a feeling about this strain. ILGM says it normally stretches between 1-2 hundred percent. I have been growing indoors in an open space, (stupid I know) this time i had a small grow tent that I built.I started pre-flowering at 13" for four days 14hurs of light 10 dark. They started stretching very fast so after 4 days went to full flower 12/12 and changed from just changing buckets when i wanted to flush to making a recurculating system. so really I knew after the first four days of the pre-flower There wouldn’t be room. I also payed closer attention to water temps. As for lights I just use the mph/mh bulbs 750 watts could go a 1000 but didn’t think it was needed

I would go to the indoor or outdoor section of the forum and ask away. I use RDWC plan to change from a 5 gallon buckets to 13 gallon buckets. 5 gallons don’t give the roots enough room IMO. GH nutrients with som hydrozime to protect the roots and some sylica to make the brnches a little stronger. I try to keep it as simple as possible but to be honest Im still learning and have a lot to learn.

Thanks a bunch

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Even 200% would be like a 39” plant. Especially if you were under metal halide. That’s definitely not normal.

Pre-flower at 13" grows a few inches for the 4 days and then full flower, you may not think its normal but it is what it is. I really don’t believe the percentage of stretch seed banks claim, I consider it just an estimate. I didnt measure the height after pre-flower but it was probably close to 20 inches. It grew very quickly during that time and for the next 2-3 weeks. (I consider Pre-flower the start of flowering, mabey I’m wrong to do that)

I did a little more research, I was growing critical mass and a lot of people get 300% stretch, so if you consider the pre-flower not part of flowering and the amount of stretch a lot of people get its perfectly “normal”. either way, I’m happy with what I got.