Compact, Cheap, and Expandable Hydroponics System

I know there are a ton of other instructables out there that deal with hydroponics but I wanted mine to fulfill a certain set of specifications. When I sat down to design my new hydroponics system for my apartment I had a few goals in mind. The system had to be cheap, since I'm on a college kid on a college budget. The system also had to be expandable, just in case I wanted to add some new plants. I really liked the ebb and flow system since it can be powered by a cheap aquarium pump and does not have to run constantly. I thought of every-day, cheap, household items that I could use for the containers in an ebb and flow system. I also needed to be able to construct everything with very limited tools. I only had a dremel with various attachments, some pliers, and wire cutters. As a result, I came up with a complete ebb and flow system consisting of a three container system and pump for around $20. If more containers were desired, it would only cost around a dollar per container.

I wanted the system to be expandable but I was also pressed for space since I am living in a very small apartment with three other individuals. The final parameters were: the system had to be easily managed and easily transported. Easily managed because I'm sometimes lazy when it comes to upkeep and easily transported because the system is not going to be set up in a permanent residence; I will be moving at the end of the semester. Since my apartment receives very little lighting I decided to make a grow light stand as well. Since grow lights can get up into the hundreds of dollars, this adds quite a bit to the total cost of the project. Although this allows you to put your plants where ever you please, it is by no means necessary as long as you have sufficient lighting.

Step 1 The Containers

The main focus of this project is on the containers. I chose the screw top Ziploc containers for the reservoirs because they formed an airtight seal but could be easily opened easily when the nutrient solution needed to be changed. The Ziploc brand containers were $2.97 for three. There are also generic brands out there that I have seen for around $2.00. For the actual pot I used the top of a 2-liter. I used these because they can usually be obtained for free. To power the system, an aquarium pump and some tubing is used. To keep the system automated, you can purchase cheap lighting timers from your local hardware stores. The complete parts list is below.

Initial Setup:
1 x $3.00 - 3 Pack of Ziploc Screw Top Containers
1 x $1.50 - Length of Aquarium Tubing
1 x $5.00 - Aquarium Pump
1 x $5.00 - Light Timer
1 x $3.00 - Silicone Sealant
3 x $0.25 - Rubber O-Ring
3 x $0.55 - Straight Connector
3 x $0.00 - Empty 2-Liter

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Total: $19.90
~ $20.00

Three Addition Containers:
1 x $3.00 - 3 Pack of Ziploc Screw Top Containers
3 x $0.25 - Rubber Washer
3 x $0.55 - Straight Connector
3 x $0.00 - Empty 2-Liter

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Total: $5.40

To make the 2-Liter containers look nicer I scrubbed all of the glue and label off. If you've ever tried to do this for other projects, it's quite a hassle. An easy way to clean the 2-Liters off is to fill them up with hot water and cap them. Next, submerge them in hot soapy water and let them sit for a few minutes. You should now be able to scrub the label/glue off with a coarse dish scrubber as shown in the pictures. The glue and label free tops can now be cut off.

To start the construction of the containers I traced the 2-Liter onto the lid and started to grind away with my dremel. It is important that you get close enough to the size of the 2-Liter while not cutting too much or too little plastic away. If you don't get a big enough hole, the lids will crack when you try to screw the 2-Liter in there. If the hole is too big, you will need to patch up a lot of space. I found these #18 O-Rings at the hardware store. They fit nice and snug around the 2-Liter. The caps need a hole for the aquarium tubing to fit through and the tube has to reach all the way to the bottom of the reservoir. When the reservoir is pressurized, the nutrient solution will be forced up into the plant. To put it all together I fit the O-Rings on the 2-Liters and screw them through the lid, applying silicone sealant to the base of the threads. I then fit the cap on and tighten. You should also smear sealant where the aquarium tubing goes into the cap to prevent an air leak. Next, the straight connectors are cut in half and holes are drilled for them. Sealant is used here as well. Remember that one of your containers will only need one port while the others will need two to pass the air pressure on.

Comments

[zgezon]

Very cool design. I am building a similar set-up for a science project, but I need to make sure that all plants are getting the same solution, so I will have one large chamber (a 3 liter bottle) with 9 hoses coming out it. Each hose will connect to a small planter. I have not built it yet, but I foresee a potential issue I wanted to know how you got around it. I need the solution to drain back into the main chamber each time the air pump turns off so it can mix with the other solutions. I worry that the air pump will maintain pressure in the bottle, not allowing the solution to drain efficiently. Did you have this issue? If so, how did you get around it? Also, when you have it up and running, how far up your planters did you have the solution rise? Thanks!

[Dandeman321]

For the level of solution, I turned the pump on, then added solution until it topped off each plant.

The way this design works, is that each plant has a sealed chamber with solution and two tubes. One for air, the other for solution/water. The solution/water tube goes straight up to the plant/gravel from the bottom of the chamber. The air tube blows air into the chamber, displacing the water, pushing it up through the solution/water tube, into the plant/gravel. When there is no solution left, the air goes though the tube, keeping all of the solution in the plant/gravel. When the pump turns off, the solution/water slowly drains back into the chamber since there is no air pressure keeping the solution/water in the plant/gravel.

I do not know of a way to have one single chamber for the solution/water unless you have a massive container (like an air tight storage container) and each plant/gravel container is on top of it.

Hope that helps.

[jerry58]

how much does this project cost to make????????????

[Dandeman321]

The instructable clearly shows how much it costs.

[jimmy005]

i gbot a question here, what sort of aquarium pump do you need? a pump for air?or a pump for water?

[Dandeman321]

Air.

[jimmy005]

thanx!! :D

[Dandeman321]

Yup!

[Tyler520]

it would be nice to find a way to make the netire system passive (no pump). A lot of people use wicks, but the wick ends up absorbing a lot of the nutrients before it gets to the roots.

Algae is also another problem...might want to paint the water reservoir opaque.

[sires6]

One more thought, Dande, is that you might be able to negate some of your problems by having some kind of drainback system.  A stiff tube fitted through the plant reservoir to the nutrient reservoir below the level of where the air will bubble through might help.  Or another tube fitted up through the cap???  I am imagining two tubes fitted through the cap???  Just a thought looking at other ebb and flow designs in google.

[Dandeman321]

If there is a tube going down to the water it would shoot up through the tube. If the tube is just a drain, then all of the air pressure will be let out. I think I understand what you're saying but I think that one would still fill up quicker and loose pressure for the rest of the system.

[sires6]

I understand what you are saying.  It might be worth a try with a one-plant system, to see what might happen.   No, the more I think about it, you have to have a kind of drain-back hose... You could try a larger size one that only comes out just inside the bottle.  I don't think you'd lose air pressure because the system is closed off with the water in the bottom of the drain tube.  And it would form a  closed system.  Initial start-up would have water coming up both, maybe, but having the drain-back lower than the in-flow would form circulation?  You could form it without plants to try.  Just a thought.  Your inflow would have to be a little faster than out flow to allow for filling of the upper reservoir.  Mmm, I'm not sure.  It was just a thought.

[Dandeman321]

Yeah, it may work. Or a water pump could be used, instead of the air pump, to suck water from the reservoirs and spit it out back up top.

[coco j]

is there anything easier then this for the light system?

[Dandeman321]

Use natural light from outside.

[sires6]

Only problem with "natural light" is that if you are growing during the winter or colder times, especially if you live in Northern Climates like New England or Germany (where I did), you don't have enough light coming in during the day and the light cycle is too short to actually grow plants.  Go to Walmart and buy a cheap $10 light fixture for flourescent lights and buy grow lights.  AS for the PVC light stand, you can get used PVC from plumbers and construction sites for free.  Just ask.

[Dandeman321]

Yeah, that's true about the natural light.

[kathy1583]

Thanks soooo much! I'm going to try this system with the grade schoolers. They will love this! Thanks for such a great and simple idea. It will be very minimal cost for the kids, since most of the items they can problably find at home.

[Dandeman321]

No problem! Hope it works out alright.

[kathy1583]

I love your idea for a small home system. I want to teach the grade schoolers how to make this type. What kind of tray did you use? Also, does the pump lead to another container or is it underneath the one in your photos? Do the containers connect with a piece of hose between each of the straight connectors or just from one connector to the next straight connector? And finally, how much water did you start with and how often do you add to the level? Can't wait to try this with the kids!!!! Thank you, thank you, thank you!

[Dandeman321]

At the hydroponics store, they had some cheap black trays. I just picked one of those up. The pump I have is in the tray, it's just a small aquarium pump. I would use 1 pump per container though, since I've had problems when I've hooked multiple containers up. There just isn't enough pressure to push the water all the way up in multiple containers. It just ends up bubbling through one. For the water, I mixed up some of the nutrient solution and poured a bit in the bottom. I then turned the pump on and just adjusted the level until it was slightly above the expanded clay/gravel. Hope this helps! Glad you're using it! You should post some pictures when you get them all setup!

[coco j]

where are these kind of stores at?

[Dandeman321]

Use google. I just noticed mine on the way home from work one day.

[coco j]

and is there any way i can make the wholes without the tools?

[Dandeman321]

You could heat up a nail and melt through it.

[coco j]

do u guys happen to have a more simpler way for me to understand how to make one of these, you know like for dummies? lol!

[jrossetti]

This is a pretty ingenious system you've designed here. I suppose there's a theoretical limit in the number of containers you can connect, based on pump output. I've seen higher output pumps, though, with 2 and 3 output nozzles, so I suspect it's possible to have a huge network of containers. This is one of those ideas I'm definitely going to have to try. Thanks!

[Dandeman321]

Well I later found out that it is difficult to balance the amount of water in each module so that all of them will bubble. Usually one fills up and starts bubbling and then the air pressure in the network drops and does not push any more water in the other ones. I pump with multiple outputs, each hooked up to one module, would work very well.

[jrossetti]

Yes, I figured this out too last night. The problem is the low pressure output from the air pump, I believe. It's possible to add a second air pump and put airstones in the base of each of the upper containers, but I feel that overcomplicates the whole system. As it is now, it's simple and elegant - and elegant in its simplicity! I think forcing it to bubble isn't terribly critical in a system this small, and since each plant has its own reservoir, that makes it exceedingly easy to correct any problems with aeration or with the nutrient solution. I've set mine up with 3 plants total: one in hydroton, one in perlite, and one as a soil-based system. I will keep you updated how they all fare.

[Dandeman321]

Very cool! Yeah, I thought that more air pressure may help but I'm unsure. It is really simple! That's how I tried to design it. I didn't want containers that would take a lot of effort to create and I wanted to make them cheaply. I wouldn't know if the plants would die without bubbling since I killed mine accidentally :( Yeah! Let me know how they work out! Hope they do well!

[hithisishal]

Thanks for the instructable! I'm thinking about building one myself, and growing a similar selection of herbs (probably parsely, basil, and cilantro). I have two questions for you: First, how are they doing? Still alive? Growing well? Second, I was wondering what your "flooding" schedule is. Have you found if you get results in the closer to 2 or closer to 5 range? Are you supposed to flood more if they air is dry (and the plant dries out faster) ? Is there anything else you can say about that?

[Dandeman321]

No problem! Well... they're all dead. The first problem was that I had some live herb plants delivered to me. They were very skimpy and barely alive. The few weeks they were in the system, they did well. Then, I went home from college for a break and I unplugged all my electronics, not remembering that the pumps and timers were also plugged into the same power strip... Needless to say, they all died, but! there was a bit of life left in the basil. It came back to life fairly quickly so that one stayed alive for awhile. If you want to do this system, I would recommend doing 1 pump per container. When the containers are connected, the air pressure can fall when one container is fully flooded, since the air leaks out when it bubbles. You can get the pumps for around 5 dollars each at walmart. The other option is to buy a more powerful pump. With more air pressure, the system should be able to flood all containers without a problem. I didn't mess around with my flood schedules much. I stuck to 2 per day, since the plants never got too big. You basically flood more the bigger the plant. I never really found out how to determine when to bump it up another flood cycle.

[hithisishal]

Thinking about it, I think that one per plant is (unfortunately) they only way to go. The problem is that as soon as one plant bubbles, the pressure in the system drops to zero. A stronger pump might actually have the effect of continuing to blow the water higher, with bigger bubbles (gaps for the air to escape), and make it less likely for pressure to be re-established in the system.

One other way to fix this might be by using valves (http://www.petco.com/product/7492/PETCO-Air-Control-Kit-for-Fresh-and-Saltwater-Aquariums.aspx?CoreCat=OnSiteSearch), and perhaps playing with the height of the plants vs. the pump. But I think, as with playing with water levels, it might be difficult to get everything just right, and will likely end up costing about as much as seperate pumps for each plant.

[Dandeman321]

Yeah, it does kind of stink. What I did instead of valves was just adjust the water levels. I got it to where they would all bubble at the same time by adding more water if it was too quick to bubble. It works for a day or two but then the plants use some of the water and ruin the balance. I really like the compact design of the containers but upon discovering this problem, I have felt they are sort of useless. I already have two pumps so I could potentially have two plants going. I didn't bring any back to college though since I didn't want to mess with it just yet.

[bustedit]

are you going to Scarborough Fair?? (couldnt resist)

[Dandeman321]

huh?

[jtroc6]

I just wanted to say you are the man! never have i seen a hydro system this cheap!!keep doing what you do man.

[Dandeman321]

Ha, thanks for the compliment.

[poppieann]

Can I use different sized nutrient containers? Say I wanted to use take out containers and they are all different sizes, will this effect the systems ability to pressurize or should I just adjust the fluid in each container?

[hilojohn]

The containers can be wider, but not taller... the air is going to push untill the lowest amount of liquid is gone then because of bubbling it will lose a lot of preassure.