Bottomfeeding: no drain, no waste

[thesloppy]

I'd love to see you give it a try! I've thought about a tail pipe (and a full on PPK) before, but I just don't have the free vertical space to play with in my cabinet. I can't even fit a small reservoir in there, so top-watering or bottom-watering is about as wide as my choices get.

 

[Chloemobile]

Too much work ;P lol. The most I may do is a float valve in the tub connected to a 5 gallon bucket to keep the rez replenished and hand water from the top once or twice a week or something.

The PPK thread is pretty long and goes into a lot of detail(really interesting thread - tons of info). I haven't found the part I read a while ago about the perched water table but I'm interested to know a bit more about it.


=D

 

[tebos]

I'm planning a DTW setup, too. Do you clean the tray itself to avoid over fertilization from the dried up water/residue?

 

[thesloppy]

I'm planning a DTW setup, too. Do you clean the tray itself to avoid over fertilization from the dried up water/residue?

I had a bunch of extra panda film, so I made tray liners for all my trays, and I can dump and wash those super easy, in between runs.

 

[StoopheadFred]

Great idea with the panda film sloppy.

Just wanted to report back with another observation on my problems. The plastic trays I used were offgassing! I wasnt sure what the deal was, but when I stopped bottom feeding I also removed the clear plastic trays I was using. As a test I put 2 healthy plants back in with the clear container and guess what? Started seeing droopy leaves and purpling/discoloration on the leaves within just a day or two.

May be obivous to others, but I didn't think about this aspect at all. I'm thinking of going with a metal tray like you've got going or a foodsafe container for my next round.

Also saw someone else on these forums mention an aqualift pump used for aquariums. It seems like these would be ideal for automating a bottom fed setup like this, because these pumps are meant for dosing precise amounts of ph'd water/ fish food or whatever they output a consistent 3.5 gallons per hour.

Tom's Aqua Lifter AW-20

They sell inline filters for a few bucks more as well. I'll be getting one of these, a filter, and a cheapo home depot timer plus a 5 gallon bucket as my res. Should cost less than $25 to have a suuuuper simple and very reliable self watering system for a basically unlimited number of plants.

 

[Chloemobile]

Would love to see how that functions once you get it all going


=D

 

[thesloppy]

Offgassing, eh? That's no fun, but at least you got the problem figured out. Similarly, I was always spooked about using metal trays, as they're going to react one way or another to being constantly wet, but I never saw any sort of problem, even though the unlined trays would get pretty funky looking. I'm using foodsafe aluminum though, so that might be of note. And like I said, I put in liners about a year ago, so now I don't have to wonder about it all.

I needed some very specific sized, square trays, with some depth to them, so I didn't have much choice in materials. They're intended to be deep dish pizza trays, if you're looking for something similar. I've kept this link to some similar, square, cake pans on my computer for years, because they've got square trays of every size, if that's of any use to you: CLICK HERE for square cake pans

 

[StoopheadFred]

Thanks for mentioning cake pans sloppy. Safeway has aluminum food trays for less than $5 in a wide variety of shapes and sizes, and by stapling some panda film to it I should have the perfect bottom feeding tray.

I've got a 5 day camping trip coming up, and so far my plants in coco/perlite hempys need to be watered 2x daily! Completely ridiculous so I went ahead and purchased 2 of those Aqua Lifter pumps. Hopefully I'll be able to have a solid running system before my trip. I'll keep you posted.

 

[InjectTruth]

Love the thread fellas. Been doin this since Dr Bud style cabs.

What do you guys think about adding perlite/lava rock/silica stone/turface/gravel/whatever to the trays inbetween the containers, to keep the water from evaporating as fast, and also functioning as additional media/rootspace. Kinda like when people clone in peat plugs on a bed of perlite in flats?

What do you guys think?

 

[thesloppy]

Thanks for mentioning cake pans sloppy. Safeway has aluminum food trays for less than $5 in a wide variety of shapes and sizes, and by stapling some panda film to it I should have the perfect bottom feeding tray.

Good thinkin'! I love finding a cheap DIY solution, and that certainly fits the bill. Good luck on your vacation!

What do you guys think about adding perlite/lava rock/silica stone/turface/gravel/whatever to the trays inbetween the containers, to keep the water from evaporating as fast, and also functioning as additional media/rootspace. Kinda like when people clone in peat plugs on a bed of perlite in flats?

Sounds good to me, InjectTruth. For bottomfeeding with any amount of standing water I personally would probably avoid perlite, strictly because it floats and will stick to your containers, and might be more of a mess versus something heavier.

 

[SRGB]

Totes designed for storage underneath beds might work well for external basins. Approximately the same value as the pans mentioned recently. They are made in a variety of sizes, the most important characteristic being low walls. The low walls might permit environmental air flow to reach the solution in the external basin, essentially utilizing the air flow of the garden as an aerator over the exposed surface of the solution in the basin.

As for evaporation of the solution in the basin, that process might be dependent on several variables; including, briefly, 1) how much solution is in the basin (depth and volume); 2) temperature of the garden; 3) dehumidification rate in the garden; 4) light intensity; 5) growth stage of the specimen; 6) root mass of the speciem in contact with the solution.

A key might be first determining approximately how much solution a given specimen
actually uptakes over a given period, then providing only that amount when the level depletes, or, to describe the process in another way, feeding only what the plant or tree requires over 24 to 48 hours, maintaining as shallow a basin as possible.

We will try to provide some illustrations of this, as long as it is alright with the OP.

Basically, the solution level in the basin would be derived from top-feeding, which accrued a run-off in the external basin at approximately 1 to 2 inches, then top-feeding would stop. The resultant `run-off` would become the bottom-fed solution over a brief period of 24 to 48 hours, at which point (see second illustration) a thin film of solution might remain in the basin. That might be the signal to water again, either by top-feeding, or replentishing the bottom reservoir. The least amount of water in the basin, the better - most stable pH and freshest solution.

We hope that this post might be helpful. If you would like for us to remove this post from your thread, please PM us or post here. Thanks.

Kind regards,
/SRGB/

 

[simple green]

These big tubs (about 2' x 3' with plenty of height for $13) in the concrete section of Lowes are perfect. I have a few of them lying around with some ideas as to how to automate and safeguard the flooding process so that once you have an idea of how much/how often you need to feed, it could easily be left alone for over a week easy with no ill effects.

I'll be back in a week or two once I get it all set up with pics/description.....

 

[thesloppy]

Nice cheap tub find, Simple Green.

We will try to provide some illustrations of this, as long as it is alright with the OP.

Looks good, SRGB! This thread could use the action.

Seeing as how there's been a tiny spike of interest in this thread, and I haven't posted any pics in ages, here's what my cabs are looking like these days. The pizza pans and panda film liners I was jabbering about earlier in the thread are pretty clear to see. Here's the right-side cab, with mom/clone compartment:

...a close up of the right side's flowering compartment:

...and the left side's flowering compartment (with the uninteresting/electronic parts cropped out):

In the interest of full disclosure, I don't religiously bottom-feed (or any other method) these guys in flowering. I will sometimes bottom-feed them, sometimes feed 'em from the top but leave them sitting in the run-off (like in SRGB's post), and sometimes I'll water from the top and discard the run-off. It pretty much all depends on my mood/interest that particular day, and I probably use each method equally throughout a 'usual' run (I always seem to be adding/subtracting/tweaking/testing something or other, so 'usual' runs aren't as constant as they should be). The moms on the other hand get bottom-fed pretty much exclusively.

 

[SRGB]

simple green:

These big tubs (about 2' x 3' with plenty of height for $13) in the concrete section of Lowes are perfect. I have a few of them lying around with some ideas as to how to automate and safeguard the flooding process so that once you have an idea of how much/how often you need to feed, it could easily be left alone for over a week easy with no ill effects.

I'll be back in a week or two once I get it all set up with pics/description.....

Hi, simple green.

There might be two sizes of those tubs, one slightly smaller than the one depicted. They might work well for smaller containers inside of them, that do not bear too much weight down on the point where the concaved walls curve into the bottom. During experiments with 20 gallon SRBGB`s filled with coco coir and pumice (approximately 80lbs), we did experience cracking of the tubs at that failure point (the curved wall transition to bottom). They should work well for containers and specimen without a significant load of media in the container, or awkward bending.

Another option might be restaurant dish buses, which are generally made to be exposed to hot water frequently; perhaps somewhat more durable.

We have been considering several options for `automatic` watering delivery methods, along with several other soilless gardeners. Soilless gardeners pusuing similar concepts are more than welcome to post your ideas in the thread The Float Valve Auto Watering Thread.

Best,
/SRGB/

 

[simple green]

SRGB: I've grown in these tubs before and supported them from the bottom without issue. Without this bottom support, I agree, they my not be able to hold substantial weight....But they'll essentially be sitting on a real low "table".

I'm planning to use a Kerick Valve (MA052) as the float and flow regulator, the raindrip analog timers for timed watering, as well as a ebb and flow fitting (with spacers) as a drain so that if there is failure and too much water fills, it doesn't completely flood the system.....

I ran timed, gravity-fed drippers for a while with success. I think that combining it with this bottom feeding method with only simplify the method. Thanks for your advice....I'll check out the float valve thread....

 

[Crusader Rabbit]

Those tubs from Lowes are great. They have straighter corners than other brands so they hold pots better. I use three of them on a table in an ebb and flow. Each 2' x 3'tub has its own 19 gallon reservoir. I can safely leave the system unattended for ten days at a stretch.

 

[Caravaggio]

You guys that are doing this what kind of PPM are you feeding your ladies?

 

[thesloppy]

I'm going to guess that most folks who bottom feed aren't taking regular PPM readings, but I could be wrong.

Personally, I use a coco mix with worm castings in it, so I shouldn't really speak too much to how folks feed in straight coco. That said, I do feed my ladies pretty light and flush early and often.

 

[dudin]

I really like this thread. Bottom feeding is where I call home (+15years of growing).
Perpetual 12/12 from seed sog bottom feeding.
Donkey dick train to g/w heaven.
Like your attitude.

Edit: I measure nothing so you are right, we bottom feeders are a lazy/practical bunch. (Cold water from the tap Epsom + organic tomatoe nutes).

 

[stoned-trout]

I have watered trays bottom feeding and done ebb and flow ..both with soil..bet it works even better in coco....yeehaw