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.
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.
Remove these ads by
Signing UpStep 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
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
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.
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
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
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.
Visit Our Store »
Go Pro Today »
http://lawn-and-garden.hardwarestore.com/75-483-drip-irrigation-fittings/drip-watering-barbed-tee-626130.aspx?utm_source=pla&utm_medium=cpc&utm_term=&utm_campaign=rkg&device=c&network=g&matchtype=
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.
The system I have made uses one large resevoir - in this case a standard 2l soft drinks bottle. The air is pumped into the resevoir at the top like normal, and nutrient exits via a tube as in the OP's instructions. The only real difference is that the tube splits into two via a three-way junction and then in to two again via two more three-way junctions before entering the planters which are also 2l soft drinks bottles. Thus the system is highly modular and expandable in powers of 2. I was initially worried that the pressure would not hold when the nutrient gets to the planters because at this point it is under 1/4 the pressure it was when it left the resevoir. But I guess the water behind it aint going anyway so the water in front has no place else to go and happily pools up into the planters. It is working fine for four planters and I would be prepared to believe that eight may work as well. I don't know what the limiting factor is, probably the size of the reservoir - but it seems even this tiny pump can handle air pressure equal to the weight of two litres of water. I'd also imagine the containers would not have to be at the same height, as long as the lengths of tubing on either side of the junctions are symmetrical.
As with Dandeman's setup it is still quite hard to regulate bubbles in this setup and I'm not sure what the limitting factor is. When the reservoir is empty and the planters full the bubbles seem to pick a left/right direction at each junction fairly arbitrarily and I don't know if that depressurises that line or what - the other three planters stay full, and one bubbles away. Perodically the bubbling planter will change for some reason and another will start bubbling but not with any regularity or predictability.
PROBLEM: The problem I am having at the moment is that even though I bought the cheapest pump I could reasonably find, it is too advanced for this project. It has a back-flow valve in it which prevents air (and hence water) from going back through the pump when the power is off - presumably to stop an aquarium from siphoning all its water onto the floor through the pump in the event of a power failure. Of course, that's not a problem for us - but the valve stops the planters from draining as the reservoir remains pressurised even when the power to the pump is off. What can be done about this problem?
Someone on another forum (I think it was youtube?) said he solved this problem by using a needle to make a tiny hole in the air line. This slowed down the speed at which the planters filled, but increased the speed they drained. I don't want to do that, it seems like an inelegant and inefficient solution to me.
In conclusion thanks for a great and helpful instructable. Any assistance that could be given regarding reservoir pressurisation would be appreciated!
The problem you're having is due to the fact that the liquid in the system serves as the seal. If it starts to bubble, the seal is lost and the system depressurizes and the units downstream do not ebb and flow. This is only problematic because you're trying to pressurize the system in series.
Instead of messing around with the solution levels in each unit, you could instead use an aquarium air distributor to pressurize each unit independently. (This also does away with the need to have both an input and an output on each container).
For example, the distributor I'm going to link can independently pressurize 4 units without messing around with the water levels:
http://www.amazon.com/4-outlets-Stainless-Steel-Aquarium-Distributor/dp/B006AY7VOI/ref=sr_1_8?s=pet-supplies&ie=UTF8&qid=1349389663&sr=1-8&keywords=air+pump+distributor
The only caveat is - the amount of liquid in each reservoir will need to be equal., since they will all pressurize at the same time. If bubbling occurs in one before the others, it will still cause the system to depressurize. But I think what I've suggested here should simplify both the design and the effort to equalize the pressure across containers.
This ability to adjust flow rate to each container could also let you use multiple size containers with the same pump. (Turn the flow rate up on a big container, and down on a small container until you the displacement rate works for all containers... just dial it in).
Algae is also another problem...might want to paint the water reservoir opaque.