I love it when my hobbies collide.
Not to hate on your hobby, but why would you grow lettuce using artificial light? Doesn't seem very economical given that lettuce is typically not very expensive
this post was submitted on 28 Aug 2025
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I'm not sure where you live, but where I'm at it feels like everything is expensive. Want a head of lettuce? That's $5. You want that same head to still be good and fresh 2 weeks later? Ha! That'll be another $5.
Whereas my 60 watt Mars Hydro (the big one) only uses $3 in electricity per month. Now the fan and the smaller supplementary light use power too. Idk how much, but it couldn't be more than the purpose made grow light. So let's call it $6 per month for fresh lettuce whenever I want it. Can't beat that with a stick, bud.
I'll have to check lettuce prices next time I'm at the grocery store, but there's no way I'm paying $5 for a head of lettuce. And for reference, those 60W running 24/7 would be close to 12€ in electricity per month for me. Growing with artificial light seems like something worth doing for e.g. super spicy chilis or cannabis (if you're into either), but I never would've thought of lettuce.
I have no experience with lettuce, but I guess ~12h of light a day would suffice, definitely not 24. So it would be more like 6€/month for you as well then.
I will note that price is from the local grocery store, because fuck Walmart. But also the main reason I grow it under artificial light instead of out in the garden is because it gets so hot here that lettuce starts to bolt in May or early June. This way I have non bitter lettuce year round.
Is this PLA or ABS? Not to be 'that guy' ^TM^ but I would be worried about microplastics and leaching if you are eating that lettuce!
Idk about ABS, but PLA definitely leeches unhealthy chemicals and will break down into microplastics in soil. It doesnt decompose.
Yup and the constant UV/moisture exposure will expedite the process, that's why I was asking!
It's PLA. I honestly hadn't considered the microplastics when using this material as a growing container. Though I do know not to use it to make cups and bowls and stuff that you eat out of.
I think my printer can print ABS, although I've never tried. Would that material be safer to grow in?
Certified food-grade PETG + food safe resin seal is the best from what I have read (I researched a bunch as I am building a greenhouse)
Thank you for the knowledge! It looks like foodgrade petg is 3 times the price and I don't plan on changing nozzles and stuff to keep everything kosher anyway. So I reckon I'll use regular petg and hit it with Shellac for the redux. Unless you have a food safe resin seal to recommend based off your research?
Thanks again!
Hobby woodworker here. Shellac is great for an initial seal, but isn't waterproof. I suggest using a two part epoxy instead. You don't need a very thick coat, so you could even use a crack filler and/or self leveling variety.
No problem - yeah that will probably be just fine, at non-commercial scale the seal will probably never get worn off and if you did ever notice spotting you can just reseal.
Unless you have a food safe resin seal to recommend based off your research?
Nope not yet! Still in the structural phase here so when I get to printing I will share for sure.
Your greenhouse design looks very cool! Consider me subscribed! Looking forward to seeing your progress.
Thanks I will share!
You two get a star for pleasant internet conversation
I just looked for a study I remembered. One has to be careful as the study is commissioned, not peer-reviewed and they clearly have an agenda with this. However there is a compelling case that PLA will break down without leaving microplastics over time. Ingestion might still not be better than PETG or ABS, but that's not really clear to me. In the long run PLA seems to be the lest bad though.
Interesting, thanks for sharing - taking this with a grain as you mentioned though.
these look really cool!
I'm new to 3D printing so this might be a dumb question but does the water or moisture degrade the plastic? I've read a lot of posts about keeping your spools out of the humidity.
Depends on the filament type. Stuff like PLA and PETG have issues like that. ABS and ASA generally don't. Outdoor stuff should generally be done in ABS or ASA (though I prefer to avoid them otherwise).
Depends on the usecase though. If it's something you could reasonably lose in nature (like markers you put in the ground, small signs and such) I'd rather use pure PHA. It will degrade of course, but that's a good thing after all. I'd rather reprint some small utilities occasionally than damaging the very nature I'm trying to foster after all.
it can make them more brittle (eapecially alongside prolonged time in the elements outside), but in a controlled environment like this it should be fine for a while :)
Sure... a typical setup strictly for growing "lettuce". Nothing else to see here...!
🤫
I love all the comments about people being worried about microplastics, as if it's not already impossible to avoid them. Don't get me wrong, adding more and going out of your way to eat plastic ain't great, but this is such a small scale fun little hobby!
You must have a massive printer to make those huge tubs though and that's what I'm intrigued by
This, the amount of potential plastic ingestion from using these pots is nothing.
It's a decent size for sure but I am constantly finding bigger stuff that I want to print that doesn't fit lol.
Elegoo Neptune 4 Pro by the way. It has been a great first printer but my next one will have a truly monster build plate.
What's even crazier to me is those don't even look like large walls! I don't suppose you could transport them like that?
I used to make (considerably smaller) hanging plant pots and boy were they thick. I really didn't want to have dirty rained down on me while watching TV haha. How well have yours held up?
The walls aren't super thick but the guy who designed this thing did a great job. I pick them up all the time, I actually take them to the sink to water them instead of taking the water to them because it's less messy.
You can find the design here: https://www.printables.com/model/762433-expanded-a-wider-planter
Wow that's crazy to me! (Am not quite as thin as I imagined) Appreciate the info and the link. Would love to hear how they're doing in another 6 months to a year :).
For sure! If I remember you'll get an update lol
have I got some almond flavored cookies for you! careful though. eat too many and you might have early organ failure, one or two should be fine though 😉
Now THAT's a good solution, so much better than trying to do it in one of those silly pod setups that don't give enough room for growth.
looks nice but that is a great way to get microplastic infused lettuce
But it tastes way better than the micro plastic infused lettuce at the grocery store.
Is it? Can you source this fact?
Looking forward to when we can print the lettuce directly.
what a beautiful image!