Hydroponic Update 26 June 2019

Just an update on the status of the floating raft hydroponic system. Earlier updates are here:



First off, I’d put one pea plant in the back corner just to see how legumes would do. After all, they typically have nitrogen fixing bacteria in the roots and I had no idea how that would impact things. Well, they love the hydroponics system. These are a small sized pea plant that is relatively heat tolerant. “Lincoln”.


Pea, Lincoln

★★★★★ 4.8 out of 5 stars. Read reviews.

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A high-yielding variety with sweet, tender flavor.

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Appropriately enough, these peas were introduced in peacetime, just after World War II. Lincoln quickly became a favorite with American gardeners thanks to its high yields and sweet, tender flavor. Suited for eating fresh, freezing or canning, the 4-5″ pods are loaded with 6-9 sweet, tender peas. Heat- and wilt-tolerant, the 18-30″ plants require staking with a small pea fence for proper support.

So reasonably good with some heat, and about 1 1/2 feet to 2 1/2 feet tall. Well I planted some of these a while back, and something got all of them in the dirt. Neat excavations rather like a bird beak. (We have some kind of crows around…) So I started more in a small pot in a tub as a wicking water supply and mote ;-) Then, some weeks ago, transplanted one of them to the hydroponic system via the expedient of just lifting it with a spoon and washing off the roots.

Here I set the pot near the hydroponic one. Clearly the hydroponics are winning. That pot has 4 plants in it, the hydroponic cup has just one. The pot has been watered with Miracle Grow along with regular bottom water supply. (Hear, drying out is my major problem with very low humidity air)

Lincoln Peas Hydroponic cup vs dirt pot

Lincoln Peas Hydroponic cup vs dirt pot

I think you can see why I’m getting very interested in hydroponics. With that kind of growth on peas, they become a very viable “emergency” food crop via hydroponics. The leaves and shoots are edible too, BTW. I’m going to look for some short stature Snow Peas and Sugar Snap Peas where you can also eat the whole pod. One of my concerns about hydroponics had been that it looked great for greens, but there was little grown in the way of starches / grains / legumes. This shows it is a viable technique for getting some “energy crops” grown too, just not done commercially for cost reasons. “Field Crops” don’t have the margin of salad greens. There’s plenty of protein in greens, along with mineral and vitamins, but they are low in gross calories. Peas are a nice starch source.

Here’s the whole tub in the front perspective:

Hydroponics Raft 26 June 2019

Hydroponics Raft 26 June 2019

Also note the other plants have really taken off too. In the front row right is “Chinese Kale” or “Chinese Broccoli” (it goes by both names) and it is doing well. Right behind it is some kind of kale / collards cross also doing quite well. (At least, that’s what they tasted like when I munched a bit). It is hard to be sure as I usually just depend on leaf shape to tell me what I’ve got and the Senposai has the same leaf shape and overall look. I’ll check my notes later and see if I wrote down who is in what spot. Also of note is that the green onions are doing great too. As I’ve historically had “drying out” issues with onions, this is a big win for me. With a mix of brassicas, peas, lettuce & saladings, herbs, onions and things like tomatoes and similar, you can put together a pretty good “survival garden” just in a closet or office space. It would certainly dress up a bunch of stored rice and beans nicely!

We’ve already had a few salads from the lettuce and today I harvested 2 plants from the back row (just after this picture). You can see that the two harvested in the front left are already re-growing and the one first harvested (just behind them) is nicely regrown too. These are all growing faster than the “Bag-O-Dirt in a tub” though it is also doing well.

Here’s what it looked like on 18 June 2019, just a week ago:

Hydroponic Tub June 18, 2019

Hydroponic Tub June 18, 2019

Here’s the image from 14 June, just 12 days ago and shortly after the transplanting:

Hydroponic Tiny Garden at 2 weeks

Hydroponic Tiny Garden at 2 weeks

So, at some point, I’m going to try some other short stature “bush” type regular beans and / or Lima Beans, but not any time soon. I already have too many beans growing in the dirt garden ;-)

FWIW, my Kratky Method bucket and tub have finally started to take off. Managing the water height has been an issue. IF your starts don’t quickly get roots into the water, a mix of evaporation and faster growing neighbors can leave them not touching the nutrient solution. Overall, I’m happier with this raft based system. Once the starts get going well, the Kratky Method seems OK, but getting to that point is a bit more complicated (especially with mixed species in one bucket / tub with different growth rates). Perhaps a restart on the Kratky Method systems using all lettuce or all peas would work better ;-)

At this point I’m entirely sold on hydroponics as an addition to the regular garden. My biggest problem now is just working out my management pattern. What to start when. How much of what to grow, on what schedule. How many tubs. All those details. It would be a LOT easier were I just trying to grow lettuce and herbs and not experimenting with a dozen things at the same time.

My suggestion to anyone else just getting started is simple: Start with lettuce. Once it is under control, add some more salad plants. Once that’s all doing fine, add an herb garden. Then think bout adding things like brassicas for asian stir fry and peas and tomatoes and all that other stuff. It will be far less complicated “out the gate” and you will have rapid success.

At this point too, I’m thinking of limiting my dirt gardening to those things not well suited to a simple hydroponics approach. That, and the winter garden when our monsoon rain patter would over fill these open tubs (until I get an indoor rack going…). So things like squash, corn, runner beans, roots like beets and carrots. All things that take a lot of space or have big deep roots.

I’ve had a lot more success with “leafy greens” along with green onions and peas in this raft hydroponics system than I’ve ever had in the dirt. The major issues in the dirt garden have been drying and bugs/snails. Both eliminated here. I’m suspecting, too, that Miracle Grow + Dirt is not as effective a fertilizer as hydroponic solution. There may well be some micro-nutrients missing in my soil, and your typical home gardener doesn’t do soil testing. It’s been a half decade since my last compost pile (when things were growing relatively well) so it may partly be the last 1/2 decade of neglect coupled with Miracle Grow alone not being an adequate “fix”.

It takes a long time to build up a good garden soil. One of the things that “Preppers”, unfamiliar with gardening or farming, too often ignore. Just having a jar of seeds in the freezer and a shovel in the garage is NOT enough. A garden is a living community that takes a couple of years to “get right” and highly productive. The biggest takeaway for me from this hydroponic testing has been that, while there are some techniques to learn, it is “instantly highly productive”. For a “survival garden”, I’d now rather have a 1/2 dozen of these tubs with foam panels pre-cut and net-cups + nutrient bag all stacked in the garage, than have a 1/8 acre of lawn and a shovel…

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
This entry was posted in Emergency Preparation and Risks, Food, Plants - Seeds - Gardening and tagged , . Bookmark the permalink.

13 Responses to Hydroponic Update 26 June 2019

  1. Quail says:

    Johnny’s Select Seeds has some excellent planting calculators. Everything from when to plant for succession harvests to calculating when to plant to avoid frosts and target harvest dates.


    Now you’ve got me thinking of trying hydroponics. I may use white pool chemical buckets and keep the water level mid way to cut down on evapotranspiration. The walls transmit plenty of light, judging by the rapid growth of algae in them. No lid so the plants still get CO2.

  2. Quail says:

    I’ve lost track of what you said about seed starting so I’ll just put this here. Sorry if it duplicates what you have already gone over.

    Combine this with Grandpappy’s starting seeds on paper towels (he also recommends tightly woven fabric) to pre-sprout and you could be looking at some serious water savings.

    “If you germinate your seeds inside paper towels then you will only need a very small amount of water to germinate those seeds. However, if you plant your seeds in seed pots indoors or in the ground outdoors, and then water the soil to germinate those seeds, then a lot of water will be wasted because you will have to saturate all the soil every day, including the soil that contains seeds that will not sprout. Please pause for a moment and think about this. It only requires a trivial amount of water to keep one paper towel moist that contains 100 seeds when compared to the amount of water required to keep the soil inside 100 seed pots moist.”


    Also in that post is seed lifespan testing he has done.

  3. E.M.Smith says:


    As algae growth in the “tank” is one of the problems with hydroponics, make sure any liquid level is light blocked (like wrap in aluminum foil).

    If using a bucket without a lid, are you saying a small circular floating raft? If so, just fill the bucket all the way as the float blocks evaporation.

    For germination tests I fold a paper towel until it fits in a square “tupperware” like sandwich container. Saturate it with water and add just a bit more. Then lay the seeds in. The lid is put in place but only about 1/2 sealed. Set on a shelf near the window in my warm-ish office.

    I check it every few days and IF it needs water, add a little. WHEN the seeds sprout, I typically then plant them into small pot in the “starter tub” with wick watering through the bottom plus some sprinkled on each day. Eventually the pot is planted out into the garden.

    For the hydroponics, I’d gone with the “recommended” rock wool and seed starter tray. I’ve also had a few seeds I’d started in other ways. Testing different methods.

    What I found is that “rock wool” has issues and is especially irritating if dry. I’ve started some other plants in other ways and generally liked it better. The rock wool does work, but with much more failure than my other ways.

    In particular, getting the plants to about 2 inches to 4 inches tall and with a couple of inches of roots in a pot, then just rinsing off the potting soil, placing it in a net-cup and surrounding it with those little ceramic balls works great. Using a paper towel rolled up and with some gaps cut in it has one raging success and one not so much. So likely has a technique issue. I think it points out why some rock wool starts fail, though. Shoving roots through stiff dense rock wool is likely hard for some sprouts.

    I’m going to try coco mat and peat pots / peat as alternatives too. But for now, my preferred method is going to be “test germinate”, put the winners into a small dirt pot in a bottom wick watering tub, then, when big enough, plant out as bare roots in ceramic balls.

    I’m also rooting some cuttings of Basil and Rosemary for the herb garden portion. I figure for the herbs, I’ll likely just run from cuttings once I’ve got something to cut from.

    I’ve also bought some fabric mesh and I’m going to test germination on it in a net-cup as an alternative to the 3 step process described above. Using quart jars, wide mouth, with the 3 inch net-cups as the nursery.

    It looks like all the ways work, it is just a matter of choosing the one you like the most with the least losses and most successes.

    It does look like once the plant is about 2 to 4 inches tall and with a few inches of roots, they just take off and rocket ride… thus my interest in getting to that stage via dirt (that I’m already very good at) or rooted cuttings.

    FWIW, this is a video the Roku YouTube app decided was right for me ;-) It is an interesting “Tower Gardening” system. I suspect it is way over priced (as nobody mentioned the price…)

    A dedicated designer system with integrated tank, pump in it, and tower segments that are clearly custom moldings.

    The guys are a bit over the top on being “thrilled” with the food quality. OTOH, I’m really liking the lettuce I’ve been harvesting ;-) That one of them does not know what chard is, was a bit of a worry point ;-)

    What I do like about the video is the number of different plants the lady is growing. Squash, cucumbers, and even peas. (Had I seen this it would have saved me running the experiment…).

    I am figuring that at some point I’m going to do a vertical garden system of some kind, so this is of interest to me. But most likely mine will be a DIY Plumbers Delight for a lot less than one of these is likely to cost.

    I do like the self contained aspect and that you can just roll it indoors when the weather isn’t quite right ;-) Garden on wheels, what a concept ;-)

  4. Larry Ledwick says:

    On the hydroponic systems I also wonder about a “dip system” where a couple times of day you dip the roots in the solution then raise them backup into the air, instead of fancy sprays to wet the roots.
    Or perhaps like a wave machine at a water park (or a wave soldering setup) where a couple times a day you generate a large wave in the tank that sloshes over the roots.

  5. jim2 says:

    That tower garden would be complete with a light kit that mounted on top for indoors.

  6. E.M.Smith says:

    @Larry L:

    The “Dutch Bucket” system is such an intermittent flow system. Usually the plant is stationary and the liquid is pumped up, then drains back to the tank. Many variations exist.

    Some do complete immersion of the roots. In other cases, it is a thin film of nutrient fluid. These are often a 3 or 4 inch PVC pipe and the solution is pumped to the top of a “plumbers delight” and then slowly drains through it back to the bottom. The pump gets turned on every so often (that can range from a few minutes on, a few minutes off, to others where there is some “medium” involved like perlite in a bucket and the solution gets pumped in one day, then drains and repeated a day or two later.

    Basically, roots need water, nutrients, and oxygen. All the rest is logistics.

    Do you bubble the air into a box full of solution and roots? (Deep Water System).

    Do you let the roots grow into a tank of solution and then slowly consume it, letting air get to the upper part of the roots? (Kratky Method).

    Do you pump a solution as a thin layer past were the roots are laying mostly exposed to the air” (Various NFT Nutrient Film Technique methods).

    Do you pump the solution as a slow flow into a bucket full of “medium” (sand, vermiculite, perlite, even sawdust or dirt have been used) where it drains back to the tank over time? (Dutch Bucket)

    Those last 2 can be continuous, fast fill / drain or slow fill / drain with various timings.

    Do you spray the nutrient solution onto the roots hanging in mid air? (Aeroponics. Also with various timings possible)/

    Folks fuss endlessly over the best air / solution mix, best schedules, etc. etc. I’m not sure there is a best…;

    There’s one system where the tank is fully close as is the root system. Air is pumped into the top of the tank, forcing solution up the “drain” (that terminates near the bottom of the tank) into the root zones. When the air pump is shut off, a slow bleed on the air lets the solution return to the tank.

    Basically any system you can think of that gets ‘enough’ oxygen and nutrient solution to the roots is a system that will work. Even stagnant solution and adding H2O2 from time to time…


    I’d guess they have lights attached to the ceiling of the grow room and just wheel the systems out on the patio when it is sunny and warm. It would be nice to have some vertical tube lights around it (say 4 of them…) providing light from all sides evenly. Would not be too hard to work up a frame using “shop light” type fixtures.

  7. jim2 says:

    EM – LED grow lights are light and easy to install into just about any shape. You could even use a 12 volt battery in case of emergency.


  8. Graeme No.3 says:

    Make sure you grow capsicums (and chillies if you like them) in summer with hydroponics. Really first class taste.
    Tomatoes also grow well (they were the original crop pre WW2). Grown large scale in South Australia under/inside shade cloth ( mesh ~ 25% shading) sheds.
    Although the Aurora project near Port Augusta has gone broke. Solar heat generation, sea water cooling and distilling to fresh, and undercover hydroponics (presumably Nutrient film method).

  9. Graeme No.3 says:

    Original method was aeroponics and attracted lots of attention with photographs of pioneer Dr. William F. Gericke up step ladder harvesting tomatoes from 20 foot tall plants. Suggest you try lower growing types.
    Nutrient film method is very popular with commercial growers in Australia. Most producers are sited near sea so don’t have to heat growing sheds.

  10. E.M.Smith says:

    @Graeme No.3:

    Here in the States most commercial growers seem to use “tables” where they have a large raft floating on it full of salad things like lettuce. For larger plants like tomatoes and cucumbers, they tend to be either nutrient film technique in fat pipes, or Dutch Bucket style. The Dutch Bucket cuts down on pumping costs as you can just wet the medium once / day or sometimes every other day. The NFT cuts down on nutrient solution as their isn’t much of it in play at any one time (but you do need to watch it and adjust the mix more often).

    I have no idea what’s common in Europe or Asia. I do know that it is a very rapidly growing field (pardon the unintended pun…) especially in places like Saudi Arabia (where they use desalinated sea water).

    Folks panicking over the need for more crop land for food production for a growing world population just don’t have a clue about hydroponics or other high yield methods. (Like “system for rice intensification” that can get a 10 x increase in rice yield). Yes, it takes more capital investment and more labor, but not very much. A very small increase in price supports it.

    Here, the push to more hydroponics has largely been driven by the quality and seasonal availability issues. Getting perfectly ripe tomatoes in mid-winter has enough price bump to pay for it. Similarly, the availability of perfect “butter lettuce” heads with zero bugs and zero pesticides has made that a majority hydroponic market. I knew this from an abstract point of view before, now I “get it” on a personal experience / emotional level. This lettuce is just divine AND easy.

    There is also a rapidly growing market for “microgreens” along with fresh herbs, salad fixings, and more in the Urban Farming movement for supply to high end restaurants. When folks are paying $30 / plate for dinner, the Chef is happy to pay up a little for ingredients picked the same day and delivered absolutely fresh, pure, and clean. With present trends, most big cities will have significant Urban Vertical Farming facilities for their restaurants in very short order. Then those folks will expand to local supermarkets and specialty stores.

    Frankly, I think the days of field farming lettuce and shipping it by rail or truck from The Southwest to NYC are pretty much done for. Field farming will increasingly be limited to “field crops” where cost is THE big driver of production. Anything where freshness and quality dominate will move toward more controlled growing and that means inside something with tight control on conditions and materials; and the limit case on that is hydroponic greenhouse production. The cost of long distance shipping will be more than the cost of hydroponic farming. (Especially if Gang Green get their way and move from Diesel trucks and trains to electricity from the most expensive and least reliable sources…)

  11. Graeme No.3 says:

    Kapiris Bros. in South Australia have switched to hydroponics for tomato growing. Their farm is 83 hectares (205 acres) but including packing shed capable of up to 1600 tonnes per day. Further info mentions 140 acres of greenhouses.
    They use drip irrigation with plastic mulch. Don’t know what that is but take it to be shredded waste plastic as picture seems to show a tray about 1 foot deep.
    Further info mentions 140 acres of greenhouses.
    For what that is worth.

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  13. E.M.Smith says:

    @Graeme No.3:

    Plastic Mulch is often just a sheet of plastic laid over the dirt. It warms the soil (tomatoes like it hot) while reducing evaporation losses and killing weeds.

    As an update:

    Today I harvested some cucumbers from my hydroponic raft system. I used commercial “Lemon Cucumbers” in a 6 pack. They seem to do Very Well in this system They do make a lot of leaf and spread out a lot, so watching the fluid level is more frequent.

    I’d often had trouble growing this cucumbers before as they like a lot of water and in our quasi-desert they never seemed to get all they wanted.

    So for me, the hydroponic system has made a success of a couple of crops I could not reliably grow before. Especially those with a high water demand where open air watering was just crazy high volume of expensive water.

    The floating rafts in the construction tubs have worked far more reliably for me than either the Kratky 5 gallon cans or the tubs. Even the aerated one. I have 2 problems (both manageable if I wanted) with the other systems.

    First off, the floats just drop down in the tubs keeping roots in water, even if I’ve neglected to check them for a few days. The ones with a solid top have the water drop away from the roots of young ones and they dry and die. The one with aeration dries out much faster as the air flow is just evaporating it a lot. The floats also act as indicators of low water level. Fix: Add a water indicator to the Kratky and tubs systems, then check them Every Single Day…

    Second, The sealed top systems ( 2 x 5 gallon cans, 2 x tubs) are more prone to root problems. For the translucent can and tubs it grew more algae, so I painted them. The styrofoam float and black construction tub only let light in in a small strip around the edge of the float. Then, with the sealed top, it can more easily go anoxic and have the roots die. It is my theory that the little band around the edge of the float is letting some air into the water AND that maybe the little bit of algae there might be aerating the water as well. Fix: Add aeration to the sealed lid systems and then be ready for more frequent water checks / solution top up.

    “Going forward” I’m going to do more of the Construction Tub / Float systems. They seem to match my style better, nest well in storage, and besides, I already have 3 more tubs – just need to add floats -) I’ll continue playing with the crates & cans to see if I can sort them out more reliably.

    One other note: Different plant species have very different ability to “get on with it’ in hydroponics. The Basil on my window sill is just loving it, even as the clear glass lets algae get going in the solution. Just doesn’t care. The Sage got grumpy about something and died (heat? roots too wet? who knows…) while the Choy and Celery next to it in the same float was Just Fine.

    As I’m quite happy with “whatever works”, so lettuce, green onions, cucumbers, squash, tomatoes, choy, peas, some herbs,… and would not mind at all if I didn’t have sage or “whatever”, that’s just not a problem for me. Just realize that some plants don’t seem to care all about things like low water one day, roots soggy the next; or algae in the soup, or whatever; while others are intolerant. So either I need to “up my game” for them or just not care…

    One other minor note: Things with really large leaf areas, like squash, cucumbers, large collard like things; they tend to suck up a lot of water / solution and will need frequent top-up. Stuff like green onions and lettuce are much slower drinkers. I think it is likely best to put one kind of plant to a tub, and only one or at most two squash or cucumbers (or other big vines” per tub. For my next added tubs, instead of a dozen holes to “pack ’em in”, I’m going to make some floats with just one or two holes for those plants. Also a more densely packed set of holes for the green onions. There’s a lot of white space between them in a 12 hole float…

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