[HN Gopher] Rack-mount hydroponics
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Rack-mount hydroponics
Author : cdrnsf
Score : 328 points
Date : 2026-03-15 04:23 UTC (18 hours ago)
(HTM) web link (sa.lj.am)
(TXT) w3m dump (sa.lj.am)
| Animats wrote:
| Years ago, when California had a really severe drought, I saw a
| large version of this to grow grass for horses. It had a stack of
| trays with lights, and each day, you harvested one tray, fed your
| horse, and replanted the tray. It was only cost-effective when
| grass hay was really expensive.
| Aboutplants wrote:
| I've seen this popping up in a few areas. In harsher winter
| conditions there are some small time farmers using this method
| to supplement their feed during bad winters.
| esafak wrote:
| I found growing my own produce to be a great way to appreciate
| farmers and my local supermarket.
| defrost wrote:
| Singapore is currently claiming title of "world's largest (and
| tallest) indoor vertical farm" with a five story, two hectare
| automated racked site (Jan 2026):
|
| https://www.youtube.com/watch?v=VJuo6Te1fM4 (2.5 minutes)
| SilverElfin wrote:
| There have been vertical farms in Singapore that went bankrupt
| previously. I don't think this model has worked very well in
| general globally, compared to traditional farms. This
| particular one is producing insanely expensive produce. For
| example the lettuce that is mentioned is over $14 a pound. It's
| also a hydroponic farm which means only some crops can be
| grown.
| shellfishgene wrote:
| I wonder if they are profitable, or if some sort of government
| support is involved. I don't think power for all those lights
| is particularly cheap in Singapore, and the competition in the
| surrounding countries has cheap labor and lots of free sun and
| rain.
| monocasa wrote:
| That's a hard thing to have introspection in as just about
| every productive source of food probably has some government
| support.
|
| Just about everywhere has understood "bread and circuses" and
| "let them eat cake" to the point of monetarily promoting food
| production.
|
| One of the big distinctions between feudalism and extreme
| capitalism in my mind is forgetting this.
| Swenrekcah wrote:
| If you look closely enough, everything is government
| supported. However farming is explicitly government
| subsidised everywhere.
| michaelteter wrote:
| Bringing necessities (water, food, energy) local is worth
| subsidizing. For those who doubt, just look at current
| events. Two morons with the right levers can upend countless
| critical processes.
| chronogram wrote:
| What's the idea behind not using capital letters?
| mvkel wrote:
| Presumably a shibboleth for human-generated content
| cowthulhu wrote:
| The author is trying very hard to look like they are not trying
| at all.
| DANmode wrote:
| or learned English chatting on the Internet?
|
| At least make it sound like you're speculating if you're
| going to.
| Gigachad wrote:
| Gen Z illiteracy crisis.
| titanomachy wrote:
| Let's not turn HN into a bunch of crotchety old men
| complaining about the youths.
| KPGv2 wrote:
| Any particular reason you didn't write a complete sentence
| but still used a period, kid?
| zdc1 wrote:
| Gen Z will often write like that, feeling that using
| capitalisation feels too "formal" for non-professional
| communication.
|
| It's feel just the next evolution in our written messaging
| dialect. Gen X had _c u l8r?_. Millennials didn 't have to pay
| per character, and got full qwerty keyboards so opted for
| normal sentences. And now Gen Z have decided that auto-
| capitalisation is unnecessary.
| fixxation92 wrote:
| I'd take all lowercase over all uppercase anyday
| benjojo12 wrote:
| I can't speak for the OPs case, but it's worth keeping in mind
| that not all languages that people are coming from have capital
| letters as a concept.
|
| I actually didn't notice the lack of caps until I read this
| comment
| agadius wrote:
| I found it pretty hard to read without the caps. I guess the
| punctuation mark is too small for my elderly eyes, and my brain
| sees it like one gigantic sentence. Perhaps the author of the
| blog is a fan of Kafka?
| DANmode wrote:
| Ctrl + "+" in your browser :]
|
| I also didn't notice the lack of caps until coming to the
| comments.
|
| ...and I'm a pedantic SOB!
| Scoundreller wrote:
| I also wondered if Jack Dorsey's shift button was broken in his
| firing tweet:
| https://xcancel.com/jack/status/2027129697092731343
| jodacola wrote:
| Is that a subtle 5th Element reference in the crontab?
|
| This is fun!
|
| The following isn't a knock on anyone doing cool stuff like this:
| I've avoided any sort of tinkering and automation of my gardening
| because I find gardening to be a slower-moving, meditative escape
| from technology. My brain shifts into a different mode (almost a
| flow state?) when I'm out working in the soil and tending to my
| plants.
| RagnarD wrote:
| All lower case, instant won't read.
| diego_moita wrote:
| Agree. It is just stupid, doesn't serve any functional purpose.
| roughly wrote:
| In this case, it seems to be serving as a useful filter
| function.
| diego_moita wrote:
| Yeah, I got the sarcasm, but that's ok.
|
| I'll water my indoor tomatoes, basil and thyme. It is way
| more productive than blabbering about gardening in the
| internet.
| jaffa2 wrote:
| I didnt even notice.
| Brajeshwar wrote:
| You did mention the reason for a server rack as a matter of
| circumstance. But if I were to do and really want the Hydropnics
| part, I'd sell the Server Rack (good price) and buy the cheaper
| Pallet Racks. The first thing that comes to mind is that it will
| be easier to plan, pluck, change lights, etc.
|
| Server Racks - you don't interact with them often, but you will
| need to with the Hydroponics one.
|
| Also, your setup is too clean. Water will drip, spill, the
| pebbles will fall. Looks really nice, though.
|
| About 5 years ago, I worked with a Climate Research Scientist
| friend, growing exotic plants in dutch-buckets, tower aeroponics,
| and rack mounted red-lit setups to induce Vitamin B-12 (only
| found in meat, so deficiencies develops in vegetarian) to Spinach
| trying to produce Super Spinash.
| yigalirani wrote:
| Op did mention that that it's impossible to get the rack out
| because they installed the doors after the rolled the rack
| cabinet in
| vasco wrote:
| It's obviously not impossible, just need to take it apart.
| defrost wrote:
| Or pry the door frame apart and tap it back in place after
| rolling the rack out.
|
| Worth a mention as many door frames are easier to remove
| than a number of people might suspect .. fewer pieces to
| disassemble than many {object}'s and not an uncommon hack
| when moving furniture.
| onlypassingthru wrote:
| Removing door frames is easy. Putting it back together
| without looking like crap is the hard part.
| malfist wrote:
| Repeat after me: caulk and paint make it what it ain't
| thunfischbrot wrote:
| For the one I have that would be irreversible. You'd have
| to cut it up.
| svilen_dobrev wrote:
| when i moved to this apartment, the wooden wardrobe i had
| in previous one (built on the spot) could eventually move
| through that door and corners but absolutely could not
| move through this doors/corridors/corners (or staircase).
| So.. i got a power-jigsaw and cut it into upper and lower
| halves. Those moved easily. Then "assembled" them halves
| with lots of metal planks and screws on the new spot.
| Tadaa...
|
| Luckily it was wooden.
| astahlx wrote:
| Having it closed (like this server rack) allows for controlled
| air circulation if fans are installed and flow paths are
| designed properly. Also, in case heating is needed, for
| example, if operated in the basement the heat loss can be
| reduced.
| mcdonje wrote:
| Tell me more about super spinach. B12 doesn't come from plants
| or animals, but from bacteria. So, I don't know how you could
| get B12 into spinach by using red lights. You'd also need to
| introduce the bacteria and somehow make it live inside of the
| spinach.
|
| Do you have some sort of inoculation step and then use red
| light to penetrate the spinach leaves to feed light energy to
| the bacteria?
| astahlx wrote:
| I also built something similar. In the end I appreciated the
| services our nature provides to us even more. Replicating all
| this artificially is really hard and energy intensive. Planting
| and growing plans outsides is fun and rewarding; adding all the
| tech in the end felt like a big waste of resources.
|
| My motivation to work on such a project was my disbelief in human
| mankind to keep our planet earth habitable.
| johnyzee wrote:
| I know this was about the journey, but for anyone interested in
| home hydroponics (without the journey of building it), I have had
| a Gardyn[1] for 6-7 years. It works well. It has a 6 gallon (20
| liter) tank and a couple of strong vertical growth lights, in a
| sleek package that looks good in the home. Plants are fitted into
| pods, in standard-size rockwool blocks that you can get from any
| grower shop.
|
| The fact that it works at all after a number of years, is
| surprising to me, given everything that goes on with it: You've
| got a moist environment with water pumped through it multiple
| times a day, fertilizer in the water crusting up in places,
| living plants with their roots growing into the pipes, algae
| growth, and a lot of parts that are shuffled around often.
|
| There might well be other systems around these days that are the
| same or better, I wouldn't know, the Gardyn is just what I ended
| up with when I researched it years ago and I'm happy with it. For
| downsides, seeds are expensive from Gardyn, but you can plant
| your own. I do buy some from Gardyn because they have a big
| selection, and they usually come out good, which regular seeds
| often don't for whatever reason. They try to push their
| subscription service but I don't need it, so don't use it.
|
| Hope this doesn't come off as advertisement, as I said there may
| well be better options (would like to hear about them), but this
| one works for me for a pretty hassle-free experience.
|
| [1] https://mygardyn.com/product/gardyn-home-kit/
| wiether wrote:
| I don't know how much fresh food costs in the US, but I don't
| see how its possible to recoup the investment on this $900
| setup in a lifetime!
|
| Then you add the electricity cost and the seeds, and the
| maintenance time...
|
| But it looks nice in a kitchen!
| buescher wrote:
| Fresh produce is pretty inexpensive here for the most part.
| But fresh herbs (like thyme, not a euphemism) are sold in
| small quantities (15g-20g) in plastic clamshell packaging in
| groceries for $2-$4 each.
|
| You don't need a $900 gadget to grow fresh herbs, either, of
| course. But that's one way you could think of it "recouping"
| the capital.
| Scoundreller wrote:
| yeah, calories are cheap: grow for flavour/value.
|
| In a backyard 5gal/19l bucket, I could get 3lbs/1.5kg of
| potatoes or 3lbs/1.5kg of cherry tomatoes. The latter is a
| better deal.
| harrall wrote:
| I wouldn't grow food hydroponically to save money, but
| growing food can get you really nice sweet varieties with
| stronger flavor than you can get in stores (since you can
| pick them at your convenience).
|
| That said, I prefer growing outdoors if you have the space.
| It's a total different maintenance (with way more bugs) but
| it also doubles as decor better than my hydroponic setup ever
| could.
| michaelteter wrote:
| If you fully measure the output (benefit) vs cost, the
| numbers don't look so bad.
|
| For example, it is known that nutrient value in produce drops
| at an astonishing rate over time; so having locally grown
| food that you can pick and eat immediately means you'll get
| vastly more benefit, beyond just calories and fiber.
|
| Also, when supply chains get disrupted and your grocery has
| empty shelves, you still have good, healthy food.
|
| You're also reducing transportation effects, which is to say
| you are having a less negative impact on the environment.
|
| Most of what we put prices on are ignoring real costs.
| fer wrote:
| What's the power consumption like?
|
| Edit: just checked the specs, 47 kWh/mo, roughly 65W on average
| tzury wrote:
| Setting aside the DIY and hacking spirit of the project, let's
| remember that, with the commonly accepted figure of 2,500
| kcal/day for an adult male, a whole iceberg lettuce (~600g)
| provides about ~87 kcal which is roughly 3.5% of what one's need.
| TurdF3rguson wrote:
| So what though? I can get all the calories I need from $0.50 of
| rice but I still need crunchy things and protein.
| rmast wrote:
| Getting all the calories you need from (plain white) rice
| just about meet minimum protein needs for a sedentary
| lifestyle (around 50g protein). For every 100 calories of
| rice there are about 2.1g of protein, so for a 2000 calorie
| diet of just rice that would be 42g protein. But eating 10
| cups of rice is a lot.
|
| Protein-wise, an all cabbage diet would give you more if
| you're meeting calorie needs - 5.1g protein per 100 calories,
| or 102g protein for 2000 calories worth of cabbage.. but that
| is a heck of a lot of cabbage (17ish lbs)!
|
| Let's be real though, people should be eating a varied diet
| and not just a single food. And perhaps not a junk food only
| diet.
| schoen wrote:
| Any issues about amino acid deficiencies from that? (as
| opposed to protein more generally?)
|
| When I was growing up, there was a vogue among my fellow
| vegetarians for the book _Diet for a Small Planet_ which
| suggested that we needed to eat a diversity of amino acids
| _in each meal_ , hence "complementary" proteins at the same
| time. This concept then seemed to fade away completely
| because it appears that the body can actually successfully
| make use of amino acids even when consumed at different
| times. But they have to be consumed eventually!
| TurdF3rguson wrote:
| It's not a complete protein, you need another source of
| protein or your body won't be able to repair tissue.
| colordrops wrote:
| Always lettuce. If someone can figure out how to grow something
| with a dense and full nutrient profile then there might be
| something to vertical farms.
| defrost wrote:
| Dyson is doing strawberries
|
| * https://dysonfarming.com/strawberries/
|
| * https://www.youtube.com/watch?v=FA6BCIWPJ30
|
| The rationale there is a combo of profit (from off season
| strawberries) and mark-up possible from unique branding (Dyson)
| and social fuzzies (eco-friendly, etc (regardless of cold
| economics)).
| jpalomaki wrote:
| Home scale example with strawberries:
| https://www.youtube.com/watch?v=8LIhx0yoM7s
| odie5533 wrote:
| I grow kale, mustard greens, herbs, and sprouts. I'm not
| looking to erase my need for produce. I just want to always
| have some fresh staples. Easier to pull off a few sprigs of
| parsley or some basil than it is to buy those little packs all
| the time.
| jillesvangurp wrote:
| The challenge is finding something that is energy dense, that
| grows quickly, and has a high value to justify the length of
| trouble you have to go through. Things like potatoes, grains,
| rice, etc. Are relatively low value and they don't grow that
| quick.
|
| Potatoes especially don't like to be submerged. But otherwise
| they are not that hard to grow. A simple grow bag will do.
| That's true for a lot of root vegetables and tubers. For
| vegetables like that, greenhouses are more common.
|
| With rice and grains, they grow well enough in hydroponics but
| you just need an enormous amount of area to get to interesting
| amounts. Also the growing season for that is quite long.
| Hydroponics favor things that you can harvest in weeks rather
| than say 2-3 times per year.
| roughly wrote:
| there's no free lunch - the plants are just rearranging what
| you give them.
| gus_massa wrote:
| I agree. Potatoes transform light into starch. With
| traditional farming you get a huge "free" solar collector. In
| vertical farming you have to pay for the light.
|
| So the alternative is to grow lettuce that has a greater
| price to energy ratio.
| roughly wrote:
| More than just light - the chemical profile of the soil is
| the feedstock for all of the interesting chemistry the
| plant does. The air can provide oxygen, nitrogen, hydrogen,
| and carbon, which are the backbone of a lot of the
| chemistry, but anything more exotic than that is coming
| from the soil. They're factories, not alchemists.
| gus_massa wrote:
| Hydrogen comes from water. They have surplus of Oxygen
| from CO2 and water, so much that they give it away.
| Carbon comes from the CO2 in the air.
|
| Other nutrients like phosphorus or potassium come
| disolved in water, but in intensive farming they must be
| added to the soil, so it's the same that dissolving in
| the hydroponic solution. Perhaps it's more efficient in
| hydroponic than in soil.
|
| Nitrogen is more tricky. There is plenty of Nitrogen in
| the air but not in a useful form, so in most cases it
| must be added as fertilizer. In some cases like soy the
| plants have helper bacteria that transform the nitrogen
| from the air into useful forms. This conversion takes a
| lot of energy, so I don't expect the lack of wind to be a
| problem, you still need some air movement to keep the CO2
| high and the O2 low. (Anyway, farming soy under
| artificial light is probably not profitable for the same
| reason farming potatoes under artificial light is not
| profitable.)
|
| The most important thing you lack inside a vertical farm
| that you get almost for free in a big faring field is
| sunlight (i.e. energy).
| zokier wrote:
| co2 is mostly free and plentiful, and also the main
| ingredient for plant biomass.
| roughly wrote:
| which is why lettuce grows just fine.
| regularfry wrote:
| I remember seeing people suggest vertical algae farms that
| could (in the marketing theory) be a very high nutrient source.
| The problem then is that you're eating algae. Spirulina is an
| acquired taste.
|
| I'm more intrigued by duckweed, which grows _very_ fast and is
| a common food in some countries.
| boomskats wrote:
| Isn't the idea that you get to do that with all the fertile
| land you liberate from the lettuce?
| zokier wrote:
| afaik soybeans can grow perfectly well in hydroponic setups,
| and I'm sure you can do many other beans too.
|
| https://pubs.acs.org/doi/10.1021/jf203275m
|
| https://www.sciencedirect.com/science/article/pii/S194439862...
| driverdan wrote:
| Fruiting plants require more space. You're not going to grow
| tomatoes or peppers in a server rack. Density works well for
| leafy greens and microgreens.
| chermi wrote:
| Mushrooms!
| DANmode wrote:
| Turns out you're meant to eat multiple plants.
|
| Bioflavonoids are important.
| kalaksi wrote:
| I've also tried a few different ways to grow plants indoors and
| I'd like to share my experiences for anyone interested. I like to
| grow indoors since I can do it year round and the environment is
| clean, stable and there are no animals or bugs (knock wood). Over
| time, I've gravitated towards low-maintenance hydroponics.
| Growing in soil needs soil, which is also dirty and so a bit more
| PITA, and it can harbor bugs.
|
| One setup I had was a vertical (hydroponic) window farm, which
| looked pretty great, but the roots start to get into the tubing,
| which I suspect could happen in the rack-mount system too. It
| also wasn't simple to just take out one plant for maintenance.
|
| A small NFT (nutrient film technique) box has worked very well,
| requires very little material as substrate and is easy to
| maintain. Might get problematic if growing the same plants for
| over a year since the roots can grow a lot and basically
| partially outgrow the system so the flow of water starts being
| insufficient and therefore might need at least some trimming and
| replanting if some of the roots start to suffer.
|
| I'm in the process of trying out deep water culture, which
| requires even less materials since there's no growing medium,
| just water, and roots are submerged so doesn't have the same
| issues as NFT. Probably has it's own problems, though, and air
| pumps can be loud!
|
| Anyhow, most of my plants are in a passive hydroponics system.
| "Kratky method" is something a bit similar. I basically replaced
| soil in pots with clay pellets and manage watering so that I have
| to water every 2-3 days. Requires clay pellets as the substrate
| so needs a bit more effort up front, but doesn't require
| electricity and is more portable when using small/medium sized
| pots. Pellets can be reused (at least most of them). I also added
| a short tube for monitoring water level and possible maintenance
| if I need to wash / flush the pot with the plant in it.
|
| Regarding fertilizing, I rarely do any accurate measurements
| anymore. I got a few pump bottles and measured how much
| fertilizer one push gets me and wrote on the bottles how many
| pushes per litre. I also eye-ball the water color a bit since I
| know how it should look like.
|
| Oh, and the plants that have done well for me, and can grow for a
| long time with multiple harvests (so no lettuce): peppers, cherry
| tomatoes, cucumbers, trying some small strawberries
| Xmd5a wrote:
| try zucchinis next (protip: the flowers needs the fresh of the
| morning to bloom).
| curl-up wrote:
| I've spent some time looking into all these methods before, but
| all of them required substantial amounts of plastic in contact
| with plants/water and in full sun/heat. Are you worried about
| leachables?
|
| To be clear, I'm not asking this in some new age way, and I'm
| sure it's better than the amount of pesti/herbicides used
| traditionally (and the whole movement behind hydro/aquaponics
| is fascinating to me), just wondering if this is something you
| ever tried minimising with such setups?
| Scoundreller wrote:
| Indoors will help with that because glass blocks a lot of the
| UV. More panes/thickness and coatings also helps
| kalaksi wrote:
| I've thought about it, but I'm not too worried. I wash
| containers before use and there's not a lot of sun or heat
| indoors. My regular pots are actually ceramic or stone. They
| look and feel better than plastic, but I also want to avoid
| unnecessary plastic when I can.
| gdorsi wrote:
| I wonder if flood and drain would work with orchids.
|
| I do that manually with my plants twice a week, they have flowers
| almost all year, but it's a chore to bring them out, flood them,
| make them drain and bring them back home.
|
| Also my wife always yells at me because I always wet the floor in
| the process.
| jszymborski wrote:
| There's a couple of YouTube channels (mainly from India) that
| claim great success with orchids and safron though I'm
| skeptical of the claims.
| jeffrallen wrote:
| I am here for exactly this kind of surprise. Nice work, HN!
| seu wrote:
| Looks great! It could be nice to have an integrated temperature
| control solution that keeps your servers cool and your plants
| warm.
| Gud wrote:
| From someone who grew a lot of weed in closets, nice work!
| Xmd5a wrote:
| Yo. I successfully did outdoor aeroponics with insane
| temperatures in the root chamber (near 40degC/100degF). My
| secret? I grew 'Virginia Gold' tobacco.
|
| > Farmers discovered that bright leaf tobacco needs thin, starved
| soil, and those who could not grow other crops found that they
| could grow tobacco. Formerly unproductive farms reached 20-35
| times their previous worth. By 1855, six Piedmont counties
| adjoining Virginia led Virginia's tobacco market
|
| https://en.wikipedia.org/wiki/Types_of_tobacco
|
| This is one beast of a plant. My plants stayed alive when I
| stopped spraying water in September and only died because of
| frost in late December. They were about 40 cm high due to the
| small volume of the root chamber.
|
| Anyway it's a great choice for an outdoor aeroponics setup.
| pm90 wrote:
| Except the tobacco part. Is this consumer grade or is it meant
| for industrial uses (organic pesticides etc).
| travisr wrote:
| What did you do with the crop?
| DANmode wrote:
| Do you smoke it?
|
| Sell it?
| detritus wrote:
| For some reason I had it in mind that growing tobacco was
| illegal in the UK, so your post prompted me to check and lo!
| Apparently it's entirely legal, for personal use.
|
| So now I have a new project - I've always wanted to smoke
| 'pure' tobacco, like the ancients.
|
| I'm twenty years too old to have an illegal harvest at home :)
|
| Next stop, need to check how to cure the leaves.
|
| Thanks!
| givinguflac wrote:
| Any of the billion guides to growing hydroponic cannabis can
| teach you how to do this in a vertical rack without issues. Neat
| write up though.
| jszymborski wrote:
| FWIW I've found ebb and flow systems work fine without the
| aerator in the water, as the roots get plenty of water during the
| ebb cycle.
| DANmode wrote:
| You mean oxygen?
| amelius wrote:
| So: 1. Convert acres of agricultural land into
| a datacenter. 2. Put plants inside. 3. ???
| 4. Profit?
| astoor wrote:
| Could be a good use for all the AI datacentres when the bubble
| bursts.
| amelius wrote:
| Sounds good: RAM chips out, plants in.
| colechristensen wrote:
| If you have cheap energy, this can be much more water-and-
| space-efficient than farming outside by eliminating pests and
| weeds and providing an ideal growing environment for the
| particular plant year-round.
| chermi wrote:
| I just love the simplicity of a cron job control system. This is
| so fun.
| gzread wrote:
| cron and ssh is the worst way to control the pump motor. If the
| network is interrupted the pump will be stuck on until the next
| cycle.
| koshinae wrote:
| This is the best thing so far on the internet I have read this
| year. Thanks.
| roshin wrote:
| I played around with hydroponics. in the end, they never ended up
| better than dirt. with dirt you have to water it, and fertilize
| every few months, but that's it.
|
| with hydroponics, every week I was refilling the water, and
| adjusting the EC and pH. The end result was very similar to what
| dirt got me
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