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Recirculating DWC (Buckets)

G

Guest

Having observed the growth and convenience of the DWC (bubbler) systems I've been using for seedlings & mother plants, I've decided to convert my flowering garden over to recirculating DWC.

Since, of course, I have my own ideas of how to build the system, I decided to start with a small test system in my larger Rubbermaid garden unit. This garden holds 3 shoebox-size containers that hold 1 gallon each. I used a small Rubbermaid container that holds 10 gallons as a reservoir and my spare 185gph pump.

I don't like making holes in containers below water level. I think that's just an invitation to a leak, sooner or later. I wanted all feed lines (nute & air) to come in above water level and the drain to be at water level. The feed lines come in at the top of the container and feed down. Air lines, of course, go all the way to the bottom to feed airstones.

Feed lines don't go all the way to the bottom of the container. Since the nutrient solution in the containers will siphon back to the reservoir if the pump goes off, I wanted some nutrient to be left in the container for the plants so the roots wouldn't dry. This also prevents the airstones from drying out. This siphon effect would allow me to easily change out the nutrient solution, leaving a small amount of the previous solution in each container. For most change-outs, this small amount makes no big difference and can be ignored; it simply makes it much easier to drain the reservoir instead of having to mess with each container. I've read one theory that the remaining amount in the container may help the plants by providing a starter mix of beneficial bacteria for the new reservoir mix.

I discovered several details that needed to be changed on the test garden, so I'm glad I built it. I mis-estimated the difference needed in depth between the drain and feed tubes and ended up with a couple of minor leaks when the position of the garden shifted slightly (it is on a stand). I discovered that the drain needs to be completely below the level of the holes for the feed lines; putting the feed line holes even with the top of the drain line risked leaks.

I also discovered that the pump was not powerful enough to circulate the nutrient quickly enough with a lift of over 2'. I raised the reservoir up closer to the garden, which improved nutrient flow, but still not enough to suit me. I am using 1/4" microtubing to feed the nutrient solution with a 1/2" drain line. To increase nutrient flow, I added a second feed line to each container. I also put some window screening over the "T" connectors at the ends of the nutrient feed lines to keep roots out. It isn't completely effective, but it helps.

I put a filter on the drain line by simply stretching it across the fitting. I found that any minor amount of root material striking the filter would block the drain, so I had to modify the filter so the roots couldn't block it.

Enough about lessons learned and on to the build!
 
G

Guest

Buckets

Buckets

The buckets I chose to use for the garden are rectangular cat litter containers. These buckets are approx 9" x 11" x 9" tall. They are a perfect size for my garden - 8 of them fit with just enough room for drains & fans. I removed the handles and painted the buckets black to block light and then white to reflect light and heat from the nutrient solution.



Lids

On my small bubblers, I use holes in the lids for holding plants that are about 3/4" diameter. These holes are too small to support a plant through flowering, so I made the holes 1.25" diameter. I use slices of PVC pipe to trace holes; the inside & outside of the pipe gives different diameters:




I cut holes in the containers using soldering irons. Small holes get made with a standard soldering tip. Larger holes get made with a circle tool that is approximately 1/2" diameter.


The tool is angled and moved around the circle to cut the basic shape. Once the shape is removed, then the circle is used to smooth out the "teeth" left around the hole.


 
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G

Guest

Drain Fitting

Drain Fitting

Holes for the drain line were made just below the reinforcement collar that held the handle for the bucket. Holes for nutrient and air lines are made above the collar where they will not interfere with the lid snapping on the bucket.


An elbow fitting that has a 1/2" threaded fitting at one end and a 1/2" barbed fitting at the other is used for the drain. The elbow fitting directs the drain line directly down so no room is wasted by having to smoothly curve the drain line down to the reservoir. This fitting is held in place with "Household Welder" contact adhesive. Aquarium silicon may work well for glass aquariums, but it is awful on plastic.

Locate the drain hole conveniently to work with your garden and reservoir. Since I had drain holes already in place from the ebb & flow garden, I located the drain holes in the buckets to use these existing drain holes.

Use medium or coarse sandpaper to roughen the surface of the plastic container to allow the glue to adhere more securely. Remove all dust with a clean cloth, insert the fitting so it dangles loosely in the hole. Put a thick bead of adhesive all around the rim of the hole on the inside. Allow it to dry for about 5-10 minutes (depending on relative humidity), then push the elbow fitting into place.

If you need to adjust the angle of the barb to aim in a direction other than straight down in order to go toward a drain, now is the time to adjust that angle. Make sure the fitting covers the entire hole. Lay the bucket down on top of something to support it (I use another bucket), make sure the fitting is still in the right position, and place something heavy on top of the fitting to hold it in place while the cement dries (I usually use books).

The cement requires 24 hours to cure, but is dry enough for a second coat in about 4-6 hours. I put a thick coat on the outside to fill in the gap between the container and the fitting and also put a thick coat around the fitting on the inside to make a smooth tapered slope around the fitting. The cement is then allowed to cure for 24 hours.

Drain fitting - inside without filter


Drain fitting - outside



Filter - Take a 5" cable tie and insert the end through the fastener to form a loose loop. Set in a handy spot. Cut a piece of fiberclass windowscreening about 1.5" x 4". Wrap one 1.5" end around the threaded fitting so the ends almost touch. Then reach for the other 1.5" end (fold the filter in half) and fold it back around the threaded fitting in the opposite direction from the first fold so they overlap. Grab the cable tie you prepared, slide it up over the screen, and tighten at the base of the threads as shown in the photo below.

Drain fitting - inside with filter



Hooking Up to Reservoir

If noise isn't a problem, an easy way to increase the dissolved oxygen levels in your nutrient solution is to allow the nutrient solution to drop back into the reservoir. I originally had the nute solution falling about 15" down to the water level in the reservoir, but it was too noisy, so I now have a hose running all the way down to water level. Since there are air hoses in each container plus two in the reservoir, I don't think there is a shortage of oxygen in the nute solution.

Since I had existing drain holes I wanted to use, I planned the drain hoses to be placed near these holes.


Since I needed to drain four containers into each hole, I needed a funnel that would fit into the hole and allow me to feed four drain hoses into it. There isn't room for a typical round funnel between the planters, I opted to use rectangular funnels designed to feed quarts of oil into a car's engine. The funnels come with a filter built into the drain and have extended tubes already on them to reach down into the reservoir.


I cut the handles off of the funnels and melted holes in the small flat end to hold the hoses from the two containers further away. The hoses from the containers touching the funnel feed straight down.


 
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G

Guest

Nutrient Feed Lines

Nutrient Feed Lines

Nutrient feed lines are located kittycorner from the drain line. If the drain is in the lower left corner, then the feed lines should be in the upper right corner. Make sure the holes are made well above the top of the drain fitting. Make the hole large enough to hold one end of a 1/4" elbow fitting.

I glued a length of 1/2" poly tubing on the inside wall of the container to hold the nutrient lines in the exact location I wanted them to be in order to allow siphoning to a certain level and no further. I cut two lengths of 1/4" tubing a bit longer than the length to reach from a 1/4" elbow (this goes through the hole at the top of the container) to the bottom of the poly tube where "T" fittings are inserted.

First, put the "T" connectors in the bottom of the 1/4" lines. I find these fittings much easier to put on by dipping the hose into some hot water first; they will stretch a bit to go over the fitting, then shrink and form to fit the barbs on the fitting, making a tight seal. Holding the two "T" fittings together, gather a piece of fiberglass windowscreen over the "T" fittings and hold it closed over the "T" fittings using a small cable tie. The end of the cable tie is cut off. Insert the 1/4" tubes into the 1/2" poly tube from the bottom, tucking the screen into the poly tube. Trim off excess tubing at the top and insert the 1/4" elbow fittings (point the fitting so it goes out the hole at the top).
 
G

Guest

Air Feed Lines & Air Hoses

Air Feed Lines & Air Hoses

The air lines are shown in the picture above next to the nutrient feed lines. The air lines can be brought in at another location if more convenient for running air lines; they do not need to be next to the feed lines.

The lines feeding from the top holes to the air hoses are made similar to the feed lines - an elbow at the top feeding to a "T" at the bottom. The "T" at the bottom fits into a length of 1/4" soaker hose. Soaker hose is a porous rubber hose used for trickling water to plants evenly. It also works pretty well for air hoses, though I make extra larger holes in the tubing every inch or so to get a good boil going in the water. The holes in the soaker tubing will eventually plug up; by making larger holes to start with, the hoses will put out air for several weeks (long enough to flower a crop). I use a nut pick to punch the holes, but an ice pick or anything along that line should work fine.


Each air hose feeds a separate circle of soaker hose; the two hoses are held in position at the bottom of the bucket by fastening them together with cable ties that have heavy stainless steel washers threaded on them to weight the hoses down.










One more tip on the air lines: Since each hose is fed separately, you can add some insurance against failure of an air pump by having each hose in a container fed by a different air pump. In other words, each air pump will feed two different plants, one from each outlet on the pump (my air pumps have two air hose outlets). If a pump should fail. the plants it feeds will still be getting air from the other pumps feeding those containers.

OK, yet another tip: Anti-siphon filters in airlines can cut the air flow by as much as 50%. In order to eliminate the anti-siphon filters and still keep the system safe, the air pumps must be mounted above water level and air lines must also be suspended above water level. I hung my air pumps and the power strip they are plugged in to from the top of the PVC frame in my garden "tent."
 
G

Guest

Reservoir & Connections

Reservoir & Connections

I built a typical manifold of 1/2" poly pipe with 16 1/4" straight fittings to connect 16 feed lines (2 lines per bucket). This manifold replaced the manufactured manifold shown in my original build thread.

I replaced the original 265 gph pump with a 635gph pump for more throughput. A couple of weeks after finishing the build while reading some information on a website, I discovered that the poly tubing I used for the manifold was only rated at about 250gph. I replaced the poly pipe with a manifold made of reinforced garden hose, which is working a lot better.


The 1/4" tubing coming from the manifold are fed up to the garden and connected to the elbow fittings that are sticking out of the holes in the container.


Figuring out max fill level in the res with this system is a bit tricky.

Background note: I use a wooden dowel as a dipstick to measure nute levels. The first time I fill the res, I stop every 5 gallons, dip the stick into the res at the pre-determined spot, and mark the water level. This allows me to estimate how much water has been used without messing around with complex systems.

First, I filled the res to its normal capacity (24 gallons).

I turned on the pump and let all the containers fill to above the level of the "T" connectors at the bottom of the feed lines, then turned the pump off. The nutes above the level of the connectors siphoned back into the res.

When the siphoning finished, I measured the level of nutes in the res. The res was down 5 gallons, so I knew each container was holding just over 1/2 gallon reserve in the bottom.

I then topped off the res to the 24 gallon mark. I turned on the pump and let all 8 containers fill to full overflow. I then re-measured the nute level in the reservoir while the system was running - this measurement is now the maximum fill level with the system running.

This measurement of max fill with system running a full capacity allows me to top off water and/or nutes each day without having to stop the pump & wait for the siphoning to finish.
 
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kilacaLIbud

Active member
holyyyy crap!!!! !ambre... u took my idea..!!!!! nicee!!!!!!

i swear ive been thinkin bout this grow room for about 6 months now... this is exaclty how im gonna start my first hydro system.. ive never seen anyone do it this way... with the square buckets and such.. but i was planin on useing 1 8 outlet pump in stead of 4 2 outlets?... or 2 4 outlets ones

:woohoo: i cant wait 2 see waht this is gonna do!!!

ambre ...u grow room design stealer... :moon:


just kidding .. wow i wanna see this runnin asapp..

amazing always ..ambre..

peace KcB
 
G

Guest

KCB-

Actually, much of this design is based on some correspondence between Sysprog and myself and some reading I did around the web. I saw a lot of potential problems with the way a lot of recirc systems are designed and wanted to see if I could come up with something different.

It's already running; I'm behind getting this written up & posted. See the "Burnin' Johnny Blaze" thread (link in my sig block).
 

Harry Gypsna

Dirty hippy Bastard
Veteran
great going ambre.... funny this, I was just saying to Dr D yestedayu that im building the same thing and wont bother to post the build thread because there r a lot about and ta'daaaa, you post one a couple of hours later hahahaha...i think thats funny...
anyway nice one Ambre....
Be lucky now
 

sysprog

Member
Ambre!!!
The catlady hydro-designer has outdone herself again! Whenever I try to explain something to anyone I find that I point them to your superbly documented posts. Here is yet another example of thinking for yourself, love the funnels. This is a great system design (growtent & hydro system) that would cost 1000s of dollars purchased retail. Many an interested new hydro grower should emulate this!

Harry, we all learn best by seeing what others have done and how they overcame their individual hurdles that we all face. If you build one, I hope to document it for us all. Doesn't have to be a tutorial as detailed as ambre's but a few pics and highlights would be appreciated by many.

Thanks ambre for all the work you put into the details and pics documenting your designs.
 

Harry Gypsna

Dirty hippy Bastard
Veteran
Oh, i will undoubtably end up posyting pics up when its going...when im back up and running that is... mine isnt one the same as this, i just meant recirc DWC when i said the same....
so areyiou happy with the way this is working out then ambre??
 
G

Guest

Sysprog- Thanks for the compliments! Part of the design is a result of our earlier exchanges on my main build thread, so some of the design credit is yours. The funnels are working out really well; I'm glad I thought of them when I was trying to figure out how to set that part up.

Harry- Don't let my thread stop you from posting yours. I don't think that there are two home-built systems that are identical. The more info & choices new growers have, the better they can fine-tune a system to fit their needs, so please go ahead and post yours.

I like the system a lot. I've discovered that that my reservoir isn't really large enough for the system. It only holds about 7 gallons more than the containers take at full fill, which doesn't give me as much buffer as I'd like. I'll be looking for some larger containers for a new reservoir that will fit in the available space, but I won't be able to switch them out until after harvest because the garden has to be lifted in order to get the reservoir in or out.

Since the water level in the res is so low, I can't risk running the pump as a submersible. When the plants get larger, it's possible they could use enough water in a day to drop the level below the intake on the pump, so I have it set up as in-line with the intake hose positioned in the lowest corner of the reservoir.
 

Harry Gypsna

Dirty hippy Bastard
Veteran
hi ambre...what you are saying about the pump and water level....i have a couple of Micra pumps made by Sicce....their umps have the inlet on the bottom of the pump...the pump sits on rubber feet and the intake is the flat surface on the bottom of the pump base...it will pump my res out to about 1 CM of water.... I have the micras but the make a whole range f bigger ones caled nova, idra, extrema and some more...they have adjusable flow on them too...
thought something like that ,might help
 
G

Guest

Harry- That pump sounds perfect for this setup, but I haven't located anyone in the USA who sells them. I'll keep my eyes open, though.

I found Sicce's website & checked them out. I assume that the round dial I see on the side of the pump in the pics is the control for the adjustable intake and not the intake itself.

Do the Sicce pumps have a filter on the intake? The pumps I use have filters on the intake and they catch quite a bit of gunk; I just cleaned the filters over the weekend. I built my own filter to put on the end of the intake hose in this unit since the built in filter only works when the pump is used submersible.
 

Harry Gypsna

Dirty hippy Bastard
Veteran
hi there.... glad it was helpful.
ye, the round dial is the control knob...the intake is like a grill in the bottom so it sits on the intake.. they have a synthetic sponge type filter inside the cover overthe intake which as you said catches all the roots,dust and other crap. Over here growell do them....maybe they could ship one over to you?? or maybe directly from Sicce??
 
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