SKU: 77169696635
hydroponic plant trays

hydroponic plant trays 10x20 Kratky Hydroponics Kit for Microgreens

$26.88 $29.87
Save 10%
No.2 Bestseller on www.warpunited.com >

Pay in installments of $7.47 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Sep 5 - Sep 10

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

hydroponic plant trays 10x20 Kratky Hydroponics Kit for Microgreens10x20 Kratky Hydroponics Tray Kit Passive Hydroponics Low Maintenance Tired of daily watering routines or worrying about your microgreens drying out when you're away for a few days? This Kratky hydroponics tray kit gives you a simple, passive growing system that keeps microgreens watered without pumps, timers, or electricityjust seeds, water, nutrients, and light. Perfect for busy schedules, weekend trips, or growers who want the benefits of

10x20 Kratky Hydroponics Tray Kit

Passive Hydroponics • Low-Maintenance

Tired of daily watering routines or worrying about your microgreens drying out when you're away for a few days? This Kratky hydroponics tray kit gives you a simple, passive growing system that keeps microgreens watered without pumps, timers, or electricity—just seeds, water, nutrients, and light.

Perfect for busy schedules, weekend trips, or growers who want the benefits of hydroponics without the complexity of automated systems.

What Is the Kratky Method?

The Kratky method, developed by Dr. Bernard Kratky, is a passive hydroponic growing technique where plants grow suspended above a nutrient-rich water reservoir. Unlike Deep Water Culture (DWC), the Kratky method uses no electricity, no pumps, and no air stones.

Plants naturally absorb water and nutrients as roots grow down into the reservoir while maintaining an air gap above the water line for oxygen exchange. It's hydroponics at its simplest.

Why it works for microgreens: Because microgreens have such short growth cycles (7-12 days from seed to harvest), they only spend 4-8 days suspended above the water reservoir. This brief contact period greatly reduces risks commonly associated with long-term Kratky growing, like root rot in mature crops.

How This System Works

During germination (3-5 days): Use the 1" no-hole tray for standard germination with blackout and weight. Seeds don't need the reservoir yet.

During growing phase (4-8 days): Transfer the mesh tray to the 2.5" deep reservoir tray filled with nutrient solution. Roots grow down into the water and absorb moisture as needed. The deep reservoir holds up to 14 cups of water, giving most crops 2-8 days between refills depending on variety and environment.

Result: Fewer daily water checks compared to traditional bottom-watering methods.

What's Included

Complete 5-Piece Kit:

  • (1) 1" Deep No-Hole Tray (10x20): Heavy-duty tray for germination phase
  • (1) 1" Deep Mesh Tray (10x20): Heavy-duty planting tray with drainage for growing phase
  • (1) 2.5" Deep Reservoir Tray (10x20): Heavy-duty Kratky reservoir holds up to 14 cups nutrient solution
  • (2) 10x20 Silicone Reusable Grow Mediums 1.2mm: Soil-free growing, works with small seeds
  • (2) Microgreen Tray Clip Labelers: For labeling and easy tray separation (color may vary)

All trays are Bootstrap Farmer heavy-duty construction (1.8-2.0mm thickness, supports 50 lbs) made in the USA.

Individual components are also available separately if you need replacements or want to expand your system.

Why This Kit Works

Low-maintenance watering: Once set up, most crops go 2-8 days without refilling. Check water levels periodically and top up as needed—no daily watering routines.

Weekend-friendly: Step away for a few days without worrying about crops drying out. The reservoir keeps roots hydrated automatically.

No automation required: No pumps, no timers, no air stones, no electricity. Just water, nutrients, light, and plants.

Flexible growing media: Use the included silicone reusable grow mediums for soil-free growing, or use soil, coco coir, vermiculite, or another medium of your choice.

Durable construction: Heavy-duty Bootstrap Farmer trays built for repeated use. These aren't flimsy one-season trays—they're designed to last.

Easy hydroponics entry: Perfect introduction to hydroponic growing without the complexity or cost of automated systems.

Best For

  • Busy growers who don't want to water daily
  • Weekend travelers who need crops to survive 2-3 days unattended
  • Hydroponic beginners wanting a simple system without pumps and timers
  • Anyone seeking low-maintenance microgreen growing without sacrificing quality

Ideal Crops

Works great for most microgreen varieties with short growth cycles:

  • Brassicas (broccoli, kale, cabbage)
  • Sunflower
  • Peas
  • Radish
  • Mustards
  • And more

What You'll Need (Not Included)

  • Microgreen seeds
  • Hydroponic nutrients/fertilizer
  • Grow light (if not using natural light)
  • Tape and markers (for labeling)
  • Water

Check our Free Fertilizer Ratio Guide for nutrient mixing instructions.

What Growers Appreciate Most

Customers often mention:

  • The simplicity of the Kratky setup
  • Fewer components compared to automated systems
  • Thick, durable trays that hold up to repeated use
  • An easy entry into hydroponics without added complexity
  • Freedom to step away for a few days without crop failure

Care & Maintenance

Tray care:

  • Hand-wash or dishwasher safe (top rack, no heat cycle)
  • Do not expose to very hot water or steam
  • Store out of direct sunlight when not in use to maximize lifespan

Silicone grow medium care:

  • Scrape off roots with scraper ( purchased separately)
  • Wash with warm water and free-and-clear soap
  • Sanitize with boiling water (1-2 minutes) when switching varieties
  • Air dry before storage
  • Typical cleanup: 5 minutes per grow

Between grows: Clean all components thoroughly, dry completely, store properly.

Product Specifications

Tray Details:

  • All trays are standard 10x20 size
  • Heavy-duty construction: 1.8-2.0mm thickness
  • Mesh Tray: 0.1475 inch mesh hole size
  • Load capacity: 50 lbs per tray
  • Material: Food-safe PP (Polypropylene) plastic
  • Made in USA

Reservoir Capacity:

  • 2.5" deep tray holds up to 14 cups nutrient solution
  • Provides 2-8 days of passive watering (variety and environment dependent)

Grow Mediums:

  • (2) 10x20 silicone reusable grow mediums included
  • Works with small seeds without soil or coco coir
  • Contains fiberglass core for structural support
  • Food grade platinum-cured silicone
  • 3rd party tested for FDA Compliance. LFGB Tested & Compliant.
  • Silicone is rated for 20 to 30+ grow cycles per sheet with proper care

Labelers:

  • (2) Tray clip labelers included
  • Design by On The Grow®
  • Color may vary

Important Silicone Grow Medium Information

Safety: Please review our Reusable Grow Medium Safety Disclaimer prior to purchase for complete safety information.

Fiberglass core construction: The silicone grow medium contains a fiberglass core for structural support. Replace your silicone if it develops tears, deep cuts, or significant wear that could compromise its integrity. For detailed guidance on when to replace, read our Silicone In-Depth Blog.

Staining: Silicone may develop stains with certain seed varieties (particularly beets and mustards). This is normal and doesn't affect performance or food safety.

NUTRITIONAL CONTENT DISCLAIMER: This product is an inert growing medium that does not add or remove nutrients from your crops. We make NO claims about nutritional content or nutrient density of microgreens grown using this product. Nutrient density depends on many factors outside our control including seed variety, water quality, light, fertilizers, and growing conditions - not the growing medium itself. We have not conducted laboratory testing and are not nutritionists. For complete nutritional disclaimer, see: [link to Safety Disclaimer page]

Warranty & Manufacturing

  • Made in USA: All trays manufactured in the United States
  • 1-Year Warranty: All On The Grow® tray kits backed by 1-year warranty
  • Tray Clip Labelers: Designed by On The Grow®, patent pending in USA & Canada

What's Not Included

This kit does not include:

  • Seeds
  • Scraper Tool
  • Nutrients/fertilizer
  • Grow lights
  • Tape or markers for labeling
  • Microgreens or plants

You may find these blogs helpful:

Simple passive hydroponics for microgreens—no pumps, no timers, just consistent results with minimal daily maintenance. 

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 77169696635

Discover Niche Categories That Outsell hydroponic plant trays

Top-Converting Item to Boost Your Average Order

4.6 ★★★★★
Based on 18 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
M
Verified Purchase
Mike B
Whiting, US
★★★★★ 5
Solid Product with Good Price`
Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited, Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited
I finally decided to use Amazon's Kindle trade-in program to trade-in my 2nd generation dinosaur Kindle for some newer tech. While my old Kindle still did work and had been a workhorse for years, the battery was not what it was, it was heavier, and the lack of back-lit light for nighttime reading was overdue for an upgrade. This Kindle is very lightweight compared to my old Kindle, even with a case (Moko, Origami Slim Shell), which I purchased as an accessory item. It is almost as light as my Galaxy S8+. The touch screen works well, which is another feature I did not have previously. I can say my only complaint here is there is little room on the sides of the case to rest your thumbs when holding the device, which sometimes causes a page turn accidentally while reading. This normally happens when reading in bed, but it's not a huge issue. The display is easy to read and I really like the paperwhite design of the display. Also, I very much like the device is backlit with a good range on adjusting the brightness as needed. I don't generally read outside much, so, for now, I have not encountered any issues. I have had the device about a month and have not needed to charge it since my first charging. I usually keep it on airplane mode and the battery is going strong. Very happy with that. The one complaint I have had with this device - and it is not the device itself, but with Amazon - the charging cable (micro-USB) lacks a power adapter enabling you to charge the device from an outlet. This was not the case with my 2nd generation Kindle as it came with the full cable and power adapter. Then, Amazon conveniently recommends you purchase said adapter as "official OEM" adapter for Kindle devices for the whopping price of $19.99. This is a complete rip-off, in my opinion. The adapter should come with the device, but if you are going to sell it separately, you do not need to over-charge for it by this ridiculous amount. You can find another generic adapter for a reasonable price. Just be sure to make sure it matches the specs required for charging the device. Booo - bad form Amazon! Even with the "missing" adapter, I am happy with the product and the value and price paid. I also very much recommend taking advantage of the trade-in program Amazone offers if you can. I was able to get a $5 credit for my old Kindle and 25% off toward future Kindle product. I also pulled the trigger on this sale during Prime Days so the device was further discounted. This was a great time to upgrade and save money.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 18, 2019
J
Verified Purchase
Jessy Nelson
Lowell, US
★★★★★ 5
Worth the money (especially if you wait for a Prime Day sale!)
Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited
I've had my paperwhite for about a month now, so I guess it's as good of time as any to properly review it. This is my first paperwhite. I got a b&n Nook Color back in 2010 for Christmas, which has served me really well over the years. However, it reached the point recently where it wouldn't hold a charge and so I found myself in the market for a new e-reader. I was drawn to the paperwhite because it was waterproof and would hold a long charge. I was a little leery about the black-and-white only nature of the paperwhite, especially as my previous ereader was in color, but so far it hasn't been an issue. I used to read comics on my Nook but haven't read digital comics in a few years, preferring print. This might be something someone who does read books with illustrations would want to take into consideration. I really appreciate the long battery life of the paperwhite. I've had it for about a month and have only had to charge it once (and it had only gotten down to about 48% so I probably could have pushed it further than I did). I've been able to read several books with the battery barely being effected. The biggest draw on battery life seems to be using the store or trying to use the rudimentary Web browser. I've been very impressed by the light, too. My Nook was impossible to read on in some lights, which hasn't been an issue at all with the paperwhite. I usually have the brightness adjusted to about the halfway point for casual reading, and brighten the screen if necessary. The brightest option COULD be a little brighter, but that's nitpicky. The device itself is VERY lightweight and portable. I have dvd cases that weigh more. My phone certainly weighs more. It's not too big or bulky to hold; I can easily hold it with just one hand. The only draw back I've really noticed is that the touchscreen is a little sensitive. Sometimes when I'm trying to scroll through my library, I end up selecting a title I wasn't trying to open. Other times, I might scroll through several pages by accidently hitting my thumb on the screen when holding the device. Buy this is a very minor inconvenience. Also, I bought the option with "special offers". They in no way to impede my reading experience. The ads show up on the main screen when the device is not in use, or in a small banner along the bottom of the "home" menu. That's it. No ads popping up during your reading.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 10, 2019
S
Verified Purchase
Sam & Jasmine
Port Orchard, US
★★★★★ 5
Impressive Product Overall
Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited, Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited
I bought the Kindle Paperwhite 2018 edition, 8 GB of storage with Special Offers for myself because up until I received it, I've been reading with the Kindle app on my Samsung Galaxy S9 phone instead. While the Kindle app on my phone was great, my eyes were really straining on the smaller screen and I'm a voracious reader. I was looking for something in a larger screen, but won't utilize the other feature and capabilities of a tablet, and beyond Kindle have no use for one at all. Overall, I'm highly impressed with this little Kindle device. I want to start by mentioning the Special Offers, as in all the reviews I read and heard about the device, the Special Offers weren't more than a footnote. They aren't intrusive at all, it's just on the main screen and that's it. They don't interrupt reading at all, and the Kindle Paperwhite personalized my Special Offers based on my reading, Kindle browsing history, and purchases so a lot of the ads that come through are actually interesting to me and in fact one or two of the ads have made me drool enough to purchase whatever book they were trying to peddle. That is definitely a plus, and yet a terrible thing because I AM such a voracious reader and I know I'm going to be spending a lot more money on Kindle books but at least the majority of the ads are tailored to the type of books I enjoy reading. I'm definitely not complaining about the Special Offers, nor will I pay to have them removed when the next ad that is displayed on my Kindle's screen might be a book I might like. Some may find the ads annoying just because it's an ad, but I find it enjoyable and definitely not intrusive in the slightest. The battery life - the Kindle came out of the box at 60% battery life and took virtually no time at all to charge to 100% on my phone's quick charger. I spent from 3 pm until almost 11 pm doing nothing but reading (when I said I'm a voracious reader, I meant it). My Kindle went from 100% battery to only 81% and from 11 pm until 8:30 am, only lost 2% battery. That is absolutely amazing to me and worth every penny I spent on the Kindle. I can't do that with my phone or a tablet; those batteries drain so quickly but this Kindle will last me all day long and still won't need to be charged at night. That's such a huge plus for a reader like me! The light on the Kindle Paperwhite is amazing, and even in my dimly lit room I don't need to have it much above 5 or 6 on the brightness. Although my phone boasts an almost 6" screen, truly the Kindle screen is much larger and thus much easier to read especially with the matte finish. My eyes strain far less on the Kindle even with almost a solid 8 or more hours of nothing but reading. This Kindle screen isn't too large, but it's definitely not too small either, it's just right. It's almost like you have a physical book in your hand, as far as relative size goes, though a little larger than your common paperback. I don't use Audible because I can't pay attention to a book when I'm listening to it being read to me, so the 8 GB of storage (more like close to 6 GB usable), holds plenty of books for me. I only have just a handful downloaded at any one point in time, but even the 10 or so books I have downloaded at once still doesn't take the storage space down anywhere near the 5 GB mark. So 8 GB is more than plenty for just regular printed books if you're like me and suddenly develop a case of A.D.D. when it comes to audiobooks. The speed of the device is just fine too. I won't say it's excellent compared to my Galaxy S9, but that's apples and oranges. For an e-reader the speed is great. There is just a little lag, but not enough to become anything beyond just barely noticeable. It's not annoying at all. It takes maybe a second or so to respond. When turning the page, even reading at a quick pace I'm able to keep up with the story on the next page from where it left off without interruption. The overall build quality is excellent. It is light weight and thinner than I expected. Yes it's plastic, but it doesn't feel cheaply made. It's comfortable to hold in one hand, or two if you like. The only thing I would change about the build is the power button - maybe I'm just used to them being on the right side of the device near the top... but the only thing I would change is the placement of the button. Overall, I'm very satisfied and impressed with my purchase. This was an excellent buy, and my next Kindle purchase is going to be one for a couple other people in my life who read just as voraciously as I do.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 25, 2019
D
Verified Purchase
Dave Regg
Chelsea, US
★★★★★ 5
Excited to read!
Digital Storage Capacity: 32 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited
This review is based on two months of daily use. I purchased a Kindle without really knowing much about them. I have always been against electronic books because I have always enjoyed the feeling of pages in between my fingers. However, circumstances have made me change my beliefs, mostly not having a nightstand with a light, and books can be bulky for a bike traveler like myself. So let me just begin with a couple of negatives. A couple of my favorite features about actual books is able to leaf back through pages and re-read portions that I misremembered, or that I really enjoyed. Reading on a Kindle makes that difficult because "leafing through" could take forever, especially if you don't recall the area in which the passage occurs. I'm also a big highlighter and margin note-taker in books so I can analyze. Although you can highlight with Kindles, for me, it's just not the same. Finally, Kindle's touch screen can be hit or miss - sometimes I will want to go forward, but the page might be back. Load times for the main screen, or cycling through, can be obnoxious. And just looking through Amazon's library to find a book? Forget about it! A lot of the novels on their suggested books, or top sellers, are "adult" novels, or easy reads. It's very difficult to find a book when you just want to discover a new author or title. Now for the benefits - my favorite feature is integrating Good Reads. It tracks my reading, the books I've read, and the books I want to read. Not only that, but it will give me suggestions based on the books I have saved or I have read. That takes care of the Amazon library problem. The backlight and the battery life are phenomenal! I can go a week without charging my Kindle, and I read it for about 90 minutes a day. It might be attributed to my backlight always being fairly low. I don't really see a reason to raise it above a third of the meter. Finally, the Kindle is small enough to fit in the back pocket of jeans. It's lightweight and waterproof. Basically, it's built for travel. As someone who walks and bikes everywhere, it makes reading on a go so much easier than carrying around a bulky or heavy book. I am grateful for this purchase. Even though it isn't an actual book, I look forward to reading on my Kindle, and if I fall in love with a new book I'm reading on my Kindle, I know that it will be worth the $15 to buy the physical copy and collect dust on my bookshelf!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 17, 2020
S
Verified Purchase
Sir Mike
Omaha, US
★★★★★ 4
Pinhole Bright Spots and Other Issues
Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited, Digital Storage Capacity: 8 GB, Offer Type: Ad-Supported, Color: Black, Option: Without Kindle Unlimited
Updated Review on Oct 6, 2019: After nearly a year of using it, I noticed that the issues I mentioned in the original review were largely negligible while reading. The pinhole near the corner was never bothersome because I'd have to remember to look very closely to see it. The battery can last for a long time during hibernation, even for many many weeks if not used. I also hardly remember to notice the uneven screen color temperature. The only thing that's still a bit inconvenient is the glare. When near a window I'd have to adjust my reading angle to avoid the glare. It's something hard to overcome with a digital device and it's not a big compromise for light-weight and convenience. Therefore please take my original review below with a grain of salt, I was nitpicking on a device that I had a lot of expectations for. I also decided to change the 3 stars to 4 stars. Original review on Nov 12, 2018 (with updates on Jan 26, 2019): I have owned a Kindle Paperwhite since 2014. I really liked that old one and gifted it away a while ago. Perhaps I have had too much expectation for this new 2018 version (waited for many months for the release), I felt quite disappointed with a few of its issues. First I must be clear that I am a fan of e-books, and I think Kindle Paperwhite has always been a nice device, light, easy to use, easier on the eyes than an LCD screen, easy to look up words, etc. I also used a Kindle Oasis for a couple of days, I don't feel comfortable with the hard slick aluminum back, and its front lights are located on the sides, so the slight uneven light can be observed from left to right; while for Paperwhite with bottom lights, the unevenness is from top to bottom, meaning within each text line, the light is usually even, therefore less distracting to reading. Here comes the new 2018 Paperwhite: I like the screen is flat with the bezels now. However, both the first device I received and the subsequent replacement have a bright pinhole dot under the screen (see photos). It's like a piece of tiny defect or dust above the e-ink text and located in the light distribution layer (my guess). When the front light is adjusted to a high level, the dot becomes quite bright and distracting. I was surprised the second device had the same issue (just my luck or something else is going on here?), but because it's near the corner, I decided to live with it. This pinhole bright spot issue apparently can be found on the previous generations as well based on many reviews, I am just astonished Amazon hasn't fixed it. Also, I don't know what happened with the charging cable, it took me a lot of effort to plug it into the device, and pull it out, it's like as if the connectors are not made well. (Update Jan 26, 2019: the difficulty of plugging in the cable only occurred during the first couple of uses, it became normal and smooth later.) Also, the screen feels easier to smudge than my old Paperwhite. The texts appear slightly blurrier where there are fingerprints. Another issue is that the screen has a ton of reflection from bright windows or light sources (please see my photo, taken under an east-facing window in the afternoon). I don’t remember if it has always been like this or it’s because of the new screen update. Even with the window blinds shut, I had to tilt Kindle to certain angles to avoid the glare, albeit softer than on an LCD screen, still quite distracting. Under the same lighting, a real paperback has no reflection glare issues. Furthermore, when front light is on and when external ambient light is somewhat dim, my replacement Kindle Paperwhite appears a bit yellower near the bottom, especially on the left side, it’s distracting but hopefully, I’ll get used to it. It’s like real paper books getting old and parts of pages turning yellow—I try to convince myself. (Update Jan 26, 2019: other reviewers have mentioned issues with poor battery life. My experience is similar that if I don't use it for a few hours, even with WiFi turned on, the device will enter something like a hibernation mode, which requires a bit more time to wake up, but it allows the battery to last for many weeks if left on the shelf. If I read about 1-2 hours a day with wifi on, the battery drains very quickly, and will hardly last beyond a week. However, If you keep airplane mode on during reading, it will significantly conserve battery, the only inconvenience is that if you don't know a word and the dictionary also doesn't have it, which is quite likely the case, Wikipedia won't be able to show up without WiFi.) Perhaps I’m just asking too much for a digital device. Overall, it’s still a great device to read books, and Amazon still provided a fast replacement when I asked. However, with these experiences, I can no longer swear to e-readers. I don’t write reviews often, but I feel strongly about this product and sincerely hope it will help fellow costumers and help Amazon improve their devices.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 12, 2018

recommand products

Aeonium haworthii 'Pinwheel Aeonium'
27.07
100mm Aeonium 'Pink Witch' Single, Rare and Live Succulent – FM succulent
28.71
Aeonium 'Blushing Beauty'
22.95
2" Aeonium ‘kiwi’
26.35
Real Live Succulent Cactus Plant : Aeonium arboreum 'Velour Green Form'
21.27