hckrnws

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.

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?

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.

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

It's obviously not impossible, just need to take it apart.

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.

Removing door frames is easy. Putting it back together without looking like crap is the hard part.

Repeat after me: caulk and paint make it what it ain't

For the one I have that would be irreversible. You‘d have to cut it up.

Yo. I successfully did outdoor aeroponics with insane temperatures in the root chamber (near 40°C/100°F). 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.

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!

What did you do with the crop?

Do you smoke it?

Sell it?

Except the tobacco part. Is this consumer grade or is it meant for industrial uses (organic pesticides etc).

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

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?

try zucchinis next (protip: the flowers needs the fresh of the morning to bloom).

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)

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.

If you look closely enough, everything is government supported. However farming is explicitly government subsidised everywhere.

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.

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.

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.

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.

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.

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/

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!

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.

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.

What's the power consumption like?

Edit: just checked the specs, 47 kWh/mo, roughly 65W on average

So:

    1. Convert acres of agricultural land into a datacenter.
    2. Put plants inside.
    3. ???
    4. Profit?

Could be a good use for all the AI datacentres when the bubble bursts.

Sounds good: RAM chips out, plants in.

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.

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.

You mean oxygen?

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.

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.

What's the idea behind not using capital letters?

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.

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

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?

Ctrl + “+” in your browser :]

I also didn’t notice the lack of caps until coming to the comments.

…and I’m a pedantic SOB!

The author is trying very hard to look like they are not trying at all.

or learned English chatting on the Internet?

At least make it sound like you’re speculating if you’re going to.

Presumably a shibboleth for human-generated content

I'd take all lowercase over all uppercase anyday

Gen Z illiteracy crisis.

Let's not turn HN into a bunch of crotchety old men complaining about the youths.

Any particular reason you didn't write a complete sentence but still used a period, kid?

I just love the simplicity of a cron job control system. This is so fun.

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.

So what though? I can get all the calories I need from $0.50 of rice but I still need crunchy things and protein.

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.

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!

Looks great! It could be nice to have an integrated temperature control solution that keeps your servers cool and your plants warm.

From someone who grew a lot of weed in closets, nice work!

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.

I found growing my own produce to be a great way to appreciate farmers and my local supermarket.

I am here for exactly this kind of surprise. Nice work, HN!

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.

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.

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.

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)).

Home scale example with strawberries: https://www.youtube.com/watch?v=8LIhx0yoM7s

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.

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.

Isn't the idea that you get to do that with all the fertile land you liberate from the lettuce?

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...

Mushrooms!

Turns out you’re meant to eat multiple plants.

Bioflavonoids are important.

there's no free lunch - the plants are just rearranging what you give them.

co2 is mostly free and plentiful, and also the main ingredient for plant biomass.

which is why lettuce grows just fine.

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.

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.

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.

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.

[dead]

[dead]

[dead]

All lower case, instant won't read.

Agree. It is just stupid, doesn't serve any functional purpose.

In this case, it seems to be serving as a useful filter function.

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.

I didnt even notice.