Watering Shelf

[DoubleDogFarm]

I have forgotten who brought this up originally. Maybe wordwiz, soil not sure.

This is the beginning of my bottom watering shelf. This shelf has a outside dimension of 24" x 12ft. This will hold (13) 1020 nursery flats.

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03112.jpg[/img]
I will be covering the inside of this shelf tray with two layers of black plastic. Black only because it is something I already have. Do you think it makes a difference? On one end, I will try to use this sink drain through the plastic and plywood.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03113.jpg[/img]
Here's another question. Will it seal? I was think about cutting a X in the plastic and pushing the four little triangles down in the hole. This may help protect the wood.
Next should I put in a layer of sand, pea gravel or lava rock? Any suggestions?

Eric

[Chaesman]

looks cool so far!!

as far as getting the drain to seal you may want to try some plumbers putty (grey stuff you use to seal drains to sinks, sinks to counters ect..)

[GardenRN]

I'll second the plumber's putty. But as always, maybe turn over the tube and see what's in it. It'd be a shame to start off by adding chems to your water. If the putty has more chemicals than you want to add, maybe use a piece of weather stripping or extra plastic to add between the bottom side of the piece of the drain that will be inside the sink so that when you tighten the assembly it makes a nice tight seal. I would think that should work just as well. OR, is you are nervous about making a drain, you could always just siphon the water out.

I think pushing the triangles of plastic into the hole may help. Also consider cutting the hole just a little small and allowing the drain piece to stretch the hole. It may make a tighter seal.

It looks great! Don't forget to angle the table just slightly toward the drain so all the water runs out. Sounds like some mundane detail that I'd overlook.

[applestar]

Would a piece/ring of softened beeswax work?

[GardenRN]

that should be perfect!!!

[DoubleDogFarm]

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03116.jpg[/img]

Just a quick update. I gave up one nursery flat space. I will be installing the sink drain as shown in picture. I will cut it off at the proper height and it will be my overflow preventer. In the side of this pipe, I will drill a weep hole. This will be the slow drain down hole.

Been thinking about the sand, pea gravel or lava rock. I decided to go with 3 lengths of PVC pipe instead. This will keep the flats off the bottom and give me a air gap, after the water drains. The air gap will hopefully prevent water roots.

Any thoughts??

Eric

[GardenRN]

Don't you want to be able to drain it completely? Maybe I'm picturing it wrong. I THINK you're saying your going to cut the drain pipe off just a bit short of the top of the shelf so if it gets close to overflowing it will go down the pipe and drain out, but you are also going to cut a weep hole in the side of the pipe for regular draining.

But if you want to drain the tub completely you'll need to have a drain basically flush with the bottom of the fixture. And I believe you'll need to drain it completely to avoid algae and mold.

I like the pvc idea! One thought on that, pvc puts off chemicals for around 1 year. after that it's cool. I know this only because if you build a PVC greenhouse and you're going to cover it with polyethylene you need to age the PVC otherwise it'll eat through the poly sheeting the first year. You don't want those chemicals in your water either. But it's up to you to decide how much you're worried about that. ou may be able to craigslist it and find some that someone has had outside for a while.

In the mean time maybe just some boards would work. Or upside down flats.
I don't mean to be blasting all of these hypocritical ideas of everything you mention man....you just get my wheels turning.

[DoubleDogFarm]

Jeff,

I don't mean to be blasting all of these hypocritical ideas of everything you mention man....you just get my wheels turning.

I like wheels turning, bring on any thoughts or criticism.

I was thinking strips of wood, easily ripped on the table saw, but algae popped into my head. Soft absorbing material

I shouldn't have any problem coming up with used or aged PVC.

Don't you want to be able to drain it completely? Maybe I'm picturing it wrong. I THINK you're saying your going to cut the drain pipe off just a bit short of the top of the shelf so if it gets close to overflowing it will go down the pipe and drain out, but you are also going to cut a weep hole in the side of the pipe for regular draining.

You are picturing it correctly. I will drill the drain hole as close to the bottom as possible. Also some one mentioned in another thread, if you block off the light, less algae. It also needs a screen / cage to keep the hole from plugging.

Applestar, I may give it a try.


Eric

[soil]

nice job! I bet the plants are going to love that new system. ever thought of adding say 1/4-1/2 inch pea gravel or something similar to the bottom. this keeps the plants off of direct plastic and when drained lets the bottoms breathe.

[DoubleDogFarm]

soil,

I'm a little concerned that the roots will grow out of the flats into the pea gravel. Would a air gap between the flats and shelf bottom prevent this?


Eric

[DoubleDogFarm]

So the shelf is in the greenhouse and partially secured. The low tunnel hoops will be removed after the shelf chains are attached.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03117.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03118.jpg[/img]

Then I put the seedlings to bed.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03119.jpg[/img]


Eric

[GardenRN]

While my brain was draining down to almost not functioning last night on night shift I had an idea that came from your shelf. I wonder if I could build three of these for inside the greenhouse. Have them on top of one another with about 3ft in between each one and have the water flow from one to the next. If say the top one slanted and drained on the left side into the next one down, and then that one tilted and drained on the right, and then back to the left again on the third, you could hold the water in the first, then drain and hold it in the second when you were ready and so on. Getting the most use out of the water. Heck you could even drain it into a 55 gal drum at the bottom and then have a pump to bring it back to the top when you were ready to water again if you wanted to. The pump would only have to be plugged in for a few minutes each time. Not much electricity being used there. Plus it would be offset by saving on the water.

Now my brain is yelling for a nap.

[DoubleDogFarm]

Jeff,

Look up Will Allen on youtube. I think his are two tier Hydroponics / Aquaponics. If the selves are to close than lights maybe needed.

Do some calculations. How much water will be needed to run a three tier system. Will it be to much for a 55 gallon drum? All the water has to go somewhere when the system is off.

I'm in the process of tearing down an old clothes washer. The drum and drain pump will be used in my Bottom Watering Shelf. The perforated chrome drum will be used to wash root vegetables and other parts for a chicken plucker. Some of the electronics maybe useful also.

Eric

[soil]

The perforated chrome drum will be used to wash root vegetables and other parts for a chicken plucker.

details lol

[DoubleDogFarm]

Details? We don't need no stinkin' details!

Soil,
One project at a time ok. I will start a new post on the plucker and one on the root washer. I make up things as I go.


Eric

[hydroguy]

soil,

I'm a little concerned that the roots will grow out of the flats into the pea gravel. Would a air gap between the flats and shelf bottom prevent this?


Eric

Fine looking project! Flood/Drain table with soil, I'm impressed.

To answer your question about roots growing out the bottom of the flats, no, an air gap will not prevent this from happening. Light and or dry air would but with your design roots growing out the bottom of the flats is just about guaranteed.

Halfway just completed an excellent grow of lettuce in the hydroponic section here at HG that demonstrates just how well roots grow in air that is dark and moist.

hydroguy

[DoubleDogFarm]

Hydroguy,

I'll have to check out Halfways lettuce thread.

So, is pea gravel the way to go? It will keep the plastic in place and the flats off the bottom. Roots may not be an issue, I'll probably prick and up-pot before.

Eric

[soil]

you want something thats not going to hold water, and something that is not too fine so it can dry out. as well as not too big for making an unstable surface. pea gravel sounds about right .

[DoubleDogFarm]

So I finished securing the shelf today. Next I laid in two layers of 6ml black plastic and started to fill with pea gravel.

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03136.jpg[/img]

Tomorrow I should be able to trim the plastic and add a wood cap.

The pea gravel has some silt in it. Looks like several rinsings before putting the self to work.

Eric

[GardenRN]

Lookin' good bro! That looks huge! I know you said it held 13 trays, but it looks gigantic!

[soil]

awesome cant wait to see how it does in action. I'm setting up a new propagation greenhouse in the next few weeks, I'm going to try and include something like yours for when I leave on trips.

[DoubleDogFarm]

Ladies and Germs, I have questions.

At what height should I cut off the drain pipe? Should the seed flats sit in 1/4", 1/2", 3/4" of water? My limitation is the 33 gallon garbage can.

The shelf is roughly 2ft x 12ft. (24sq ft) 2" of water is 1/6 of a cubic foot. So 1/6 of 24sq ft = 4 cu ft. 8 gallons to a cubic foot. 4x8 = 32 gallons.
How did I do. Is this correct? Yes, the gravel take up space also.

How big of a weep hole (drain down) should I drill in the side of the drain pipe. Should I base it on time? Do I fill the self quickly and let it drain slowly. Is it better to leave the pump running for a length of time and drain down quickly.

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03148.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03154.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03153.jpg[/img]

Eric

[GardenRN]

Eric I'd say the weep hold needs to be the size of whatever stopper you have to put in it. You should be able to plug it in case you decide you want to. And as far as cutting off the top of the pipe, provided it can drain at at least the same rate you will be filling the shelf, cut it off right beneath the "critical" level (the level at which it would start doing damage).

I would make it so that when your seed trays are in those flats, the bottoms are in the water about 1/4 inch. But that's just how I do things.

Lookin good!

[hydroguy]

Ladies and Germs, I have questions.

At what height should I cut off the drain pipe? Should the seed flats sit in 1/4", 1/2", 3/4" of water? My limitation is the 33 gallon garbage can.

The shelf is roughly 2ft x 12ft. (24sq ft) 2" of water is 1/6 of a cubic foot. So 1/6 of 24sq ft = 4 cu ft. 8 gallons to a cubic foot. 4x8 = 32 gallons.
How did I do. Is this correct? Yes, the gravel take up space also.

How big of a weep hole (drain down) should I drill in the side of the drain pipe. Should I base it on time? Do I fill the self quickly and let it drain slowly. Is it better to leave the pump running for a length of time and drain down quickly.

Eric

Water displacement by your rocks is a much larger factor than your giving it credit, I had a system once that held 40 gallons and when it was filled with hydroton (rocks) it filled with 12 gallons of water. Just an example for you to consider.

Couple other things to think about: general rule of thumb is the discharge is normally 50% larger than fill line. I run 1/2" fill and 3/4" drains.

Screens are important for fill and drain fittings. Obviously rocks don't float but (and this is important) when the pump turns off the water will drain back down into the resv through the pump. A check valve would prevent this but that would keep the tray filled at all times and you don't want that. So a screen on your fill line is really important.

I'd hate to think about leveling a system the size your building and getting complete coverage with 1/2" of water. Personally I'd go with a deeper flood level and use the rocks to get your trays up and leveled for what ever flood deepth you want in the flats, not necessarily the flood depth of the structure.

Great work and I'll be watching to see how this system works!

hydroguy

[DoubleDogFarm]

So I ran a test this evening. I did not time anything.

Filling was really fast and the table seems pretty level.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03156.jpg[/img]

Looks like I need to lower the stand pipe and maybe increase the drain hole too. The drain hole is only 1/4"
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03158.jpg[/img]

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03162.jpg[/img]

I had to turn off the pump, looked like the inflow was overtaxing the out flow
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03164.jpg[/img]

I also don't like how the plywood underneath is getting wet.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03163.jpg[/img]

Eric

[GardenRN]

ah yeah, that shouldn't be getting wet. Is the drain pipe cut off even with the wood? If so maybe you could get some of that plastic paint and put it around there to help protect the wood. Or a can of spray-o truck bed liner would work good. They have it at advanced auto here for like $8 a can.

[DoubleDogFarm]

Jeff,

If you look back on page 1 you will see the sink drain is flanged on the one end. It's up against the bottom.

Couple more questions.

How long should the flats sit in the water? I have no experience with bottom watering.

How do I keep the seed starting mix from fall out. I'm using 1020 nursery flats? Do you think Coir will work?

Eric

[GardenRN]

I don't know what coir is but...

If you're talking about the same 1020 cells I am thinking of with small holes in the bottom, don't worry about it falling out. You may have a very tiny bit fall out but once it's wet it sticks together and stays in the cell pack.

Depending on your mixture it could take different amounts of time for the water to wick to the top of the soil. When I water mine, I pour in enough water to come about 1/4 inch up the side of the cells. Then it takes about.....eh.....roughly an hour I guess before the soil is wet at the top. I am using roughly a 50-50 mix of garden soil and jiffy seed starting mix.

If your mix is completely dry sometimes it takes overnight to wet everything and it may benefit from a good spray of water on the top. I'd say put your flats in the water and see how long it takes them to get wet at the top. Then you have a reference.

I see the flange...but if the plywood is getting wet, it's only a matter of time before it rots, or just as bad, warps. Gotta find a way to protect that plywood where the water is pulling off the side of the flange and getting it wet.

P.S. while I was typing this I googled coir, I don't think that's necessary at all. I bottom water everything (just started this year) and not only does it save me time, I don't lose any starting medium from bottom loss. I was concerned about that as well at first. Cutting up all that coir to fit in the bottoms of the cells would be insanely tedious.

[DoubleDogFarm]

Thanks Jeff,

P.S. while I was typing this I googled Coir, I don't think that's necessary at all. I bottom water everything (just started this year) and not only does it save me time, I don't lose any starting medium from bottom loss. I was concerned about that as well at first. Cutting up all that Coir to fit in the bottoms of the cells would be insanely tedious

Coir comes in liner rolls. Easy to cut and fit.
https://www.windowbox.com/coco-roll-8.html?

Also I'm using 1020 open flats. They have some mesh on the bottom, but not enough. The tray floating in the water. Large diamond pattern.

Eric

[soil]

wow overnight to bottom water, thats a long time your soil must be dense or hydrophobic.

my cells are solid wet within 2-3 minutes.

the mix I use is

compost
sand
rice hulls
ewc

equal parts.

if I were you I would just make sure to be there the first few times you fill it, so you can keep track of the time it takes for your soil mix to fully saturate. once you have a baseline you can set up a timer if you wish.

[GardenRN]

Soil, I don't know that it took all night. But when I was using just the jiffy seed starting mixture, it comes out of the bad dry as a bone and very fluffy. So it took the water a while to wick up because I didn't pack it down at all. In retrospect I guess I should have. It would have moistened faster. But I know that after about 20 minutes of messing with other stuff after I watered it, it was still bone dry on top. The stuff that mixed which was half and half jiffy and garden soil was wet in just a few minutes. I think it's just one of those things how, even in the garden, if soil gets totally dried out, it almost repels water until it moistens up a bit.

[DoubleDogFarm]

One step closer.

I flushed a lot of the sediment out.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03166.jpg[/img]

Oh-yeah, duh moment. I was worried about the water inflow being too much for the stand pipe outflow. Just throttle back the pump, dummy. I installed this Y valve so I could drain the whole system. It works as a throttle also.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03168.jpg[/img]

Soil, a timer is definitely a wish

Eric

[DoubleDogFarm]

This is probably way to many photos for dial-up folks, sorry.

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03175.jpg[/img]

Here I have 11 flats on the Bottom Watering System. This is 198 4" pots.
There are no seeds in them, just testing the wicking. The mix is peat and perlite. Looking good so far. Water has wicked about 3/4 the way up.

Time to clean the windows.
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03179.jpg[/img]

Still need to fix the stand pipe and buy a timer.

Eric

[GardenRN]

Wow! Looks great! How long did it end up taking to wick all the way up? Just curious how your mix did. Don't forget it will probably not take as long the second time. Once it has done it once the soil settles and it wicks faster the next time, at least in my experience.

Where do you get all of your pots from for selling at the FM? Buying them online or a cheaper source?

[DoubleDogFarm]

Jeff,

The wicking test was about an hour. I'm thinking from now on it will be minutes.

Where do you get all of your pots from for selling at the FM? Buying them online or a cheaper source?

No Way! I'm to cheap. From my brother the landscaper. Also our local landscape material yard has a nursery pot recycle area. Many hundreds from them. My clients also return containers to me. All free.

Eric

[GardenRN]

Sweet! I was thinking about asking up at the nursery here but I figured I'd wait till summer when there's a lot more of them. Doubt they have many this time of year.

Maybe I should call a landscaping company and ask.

[The Mad Hatter]

That's a really cool project Eric! Making me think about the room I got in the basement.

T.M.H.

[DoubleDogFarm]

Jeff, Look around. The pots are out there.

THM, Thank you. My brother came over yesterday and one of the first things he said, "Now you can build one above this one" When will it end?

I also planted seed yesterday.
Valmaine lettuce
Red Sail lettuce
Buttercrunch lettuce
Speckles lettuce
Winter Red kale
Joi Choi
Bloomsdale Spinach
Tah Tsai
Belstar broccoli
Champion collards
Leeks
Bright Lights swiss chard.

12 flats = 216 - 4" pots

Eric

[DoubleDogFarm]

More pictures

The Joi choi and Tah Tsai are way ahead of the rest. I see a few lettuce just starting.

[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03188.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03189.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03192.jpg[/img]
[img]https://i67.photobucket.com/albums/h300/eric_wa/Double%20Dog%20Farm%20%20Greenhouse%20Propagation/DSC03191.jpg[/img]

Starting to snow

Eric

[GardenRN]

We got a stinkin flurry here yesterday too Not happy about it. But the day ended at 45 degrees so I guess it's not quite worth cursing. But for now everything is still crammed inside.

[img]https://img.photobucket.com/albums/v687/grnpez/Photo02231154.jpg[/img]


Gonna have to open this up soon to transplant tomatoes, peppers, basil, squash (that I still don't know why I started inside), and lavender. And I still have to harden off all the cabbage, broccoli and lettuce!