DWC: Recirculating VS Constant Recirculating - Page 2

hydrolized · 08-28-2009, 06:05 PM

Quote:

Originally Posted by Dr. Funkenstein

Do you suppose the Uniseals would be sufficient enough to prevent leaks at the lower end of the buckets, had you been using the square 8 gallon buckets, as depicted in the Under Current system? I'm unsure of the exact wall thickness of those square buckets though.

I was considering locating these and using them in place of the round buckets to make the construction phase easier.

Have you been having algae problems with your pvc run? Is this why you have it wrapped in insulation?

I can't really predict if they would work or not...it depends on a few things from what I have experienced/read...the wall thickness being one and the roundness/cleanliness of the hole edge being the other main issue...on my buckets I used a 3" high quality hole saw and spent about 20 minutes per bucket with a razor blade/fine sand paper to deburr the holes and make them perfectly clean and I still had leaks. I'm sure if the buckets were thicker and there was most surface area for the rubber to seal against they would have worked. During my research I did when I first had leaks I found many people use them to pretty high pressures with great success but these are aquarium people using thick plastic tanks...everyone who have a problem had a ragged or out of round hole, or too thin of a tank. I don't believe the curve of the bucket was part of the problem, the amount of sealing surface did not change as much as I thought it would.

The end user of the system did bring the water level up an inch above the feed lines when she was rooting cuttings and one 3/4" uniseal drip leaked on her...the Uniseals are actually tapered and the part that seals against the thin bucket is the smallest O.D. of the whole uniseal, I would say if your using buckets or have walls smaller then the min spec. don't use them.

I went for them at first because the user wanted simple pull apart disassembly for cleaning, and the price, but after installing them I realized you need A LOT of strength to get the pipe in and out of the uniseal..it took me an hour and a lot of sweat/windex to put together 16 pipe/seal connections, using walls for leverage and all my body weight at times! after finding leaks, draining, fixing, filling, finding more leaks, I got fed up and reluctantly searched for bulkhead fittings, since the cheapest of those I saw were around $12 compared to $4 for the Uniseals, and luckily I found some nice 2" PVC ones for $5 so I went with those. The way I have them set up you can still take apart the system by unscrewing the bulkhead from the buckets so it is still user friendly, and absolutely leak free as of the last time I talked to her, about 6 months running.

There have been no algae problems, and yes the reflectix was wrapped around the pipe and buckets for light penetration issues first, and second because the chiller was added. When the user first ran the 1kW MH to dry test the room for ventilation, there was no insulation on the PVC in the room. When the door was shut and the lights in the outer room turned off, that little piece of 2" PVC you can see returning to the pump bucket was literally GLOWING...showing me that SCH40 PVC is NOT thick enough to keep light out, at least at 1kW intensities.

Sorry it's hard to see, but that glowing thing is the return pipe under the 1kW....I can only imagine how bright it would be inside all the piping directly under the light...without proper precautions (BB) in your nute recipe the unprotected piping would be an algae factory....some people have open reservoirs in the room and never have a problem..others can have a pinhole light leak and have a algae problem in a few hours, depends on too many factors to list really...I would just cover everything up..reflectix is cheap and it doesn't take long and is much easier to do when you are still in set up stage than when you have some 4' monsters in your system.

I like the fact that you are choosing the DIY route, you get a much more customized system, at a MUCH cheaper price.

Dr. Funkenstein · 08-28-2009, 09:14 PM

Thanks a lot, man. You've been extremely helpful, and this is all very informative. I was wondering what formula you are useing to calculate your pump requirements.

Also, you say the upper runs are the fill, and the lower runs are the drains. Could I completely cut out the use of the upper runs, and use a single run near the bottom of the buckets to flood and drain, if I use the appropriate Bulkhead fittings?

I'm trying to cut out as much clutter in the grow space as possible. I want to try to run the system on a single aqua pump, and air pump for the air-stones.

Also, what is an MPT? Sorry if these are dumb questions.

hydrolized · 08-29-2009, 12:43 PM

Quote:

Originally Posted by Dr. Funkenstein

Thanks a lot, man. You've been extremely helpful, and this is all very informative. I was wondering what formula you are useing to calculate your pump requirements.

Also, you say the upper runs are the fill, and the lower runs are the drains. Could I completely cut out the use of the upper runs, and use a single run near the bottom of the buckets to flood and drain, if I use the appropriate Bulkhead fittings?

I'm trying to cut out as much clutter in the grow space as possible. I want to try to run the system on a single aqua pump, and air pump for the air-stones.

Also, what is an MPT? Sorry if these are dumb questions.

No question is a dumb question on here! That's how you learn! It's great to get first hand experience about things...ive made the mistake of going by books and hearsay about stuff and fucked up before (ask DrDankman lol)....

Pump requirements I calculated from researching peeoples grow journals and the GrowFAQ...I heard from LukeHighwalker that someone on here (forget the name, SORRY!!) was running 2000cc/min/gal and it was working great, so I went with that as a target number for the test system...and it worked great so I applied it to all the systems I design.

Something I learned about oxygenation while researching this is that the actual bubbles going through the water don't really transfer that much O2 to the solution due to surface tension, it is when they break the surface of the water at the top of the bucket and mix the solution with the root zone air where most of the O2 transfer occurs. Knowing this, I made the feed lines as high as possible, so in addition to the bubble diffusers there is the "waterfall" effect which also aerates the solution...nice to have if your air pump fails IMO.

Yes the top lines are the "fill" lines, but they don't really fill anything, they are just circulating the nutrient solution. The buckets are always full of water as this is a DWC system.

I don't see a problem with reversing the flow and making it into a F&D setup, but I would leave the feed lines and in turn they would turn into the drain lines/hieght controllers (kind of like a ebb and flow fitting, the water will rise until it gets to the feed lines then drain back into the control bucket. could just plug the pump into a timer for the feeding (wet) time...I've always been a fan of DWC so I really don't know much about F&D.

Dr. Funkenstein · 08-29-2009, 04:04 PM

Thanks, man. My replies are in bold.

Quote:

Originally Posted by hydrolized

No question is a dumb question on here! That's how you learn! It's great to get first hand experience about things...ive made the mistake of going by books and hearsay about stuff and fucked up before (ask DrDankman lol)....

Yes, this is what I've been dealing with. It's so easy to be mislead by the company salespitch, and makes a world of difference when you hear about all the stuff company's, and books fail to tell you. I appreciate it greatly.

Pump requirements I calculated from researching peeoples grow journals and the GrowFAQ...I heard from LukeHighwalker that someone on here (forget the name, SORRY!!) was running 2000cc/min/gal and it was working great, so I went with that as a target number for the test system...and it worked great so I applied it to all the systems I design.

Were they running the same number of buckets as you were planning on running when you were doing your research and planning, which is why you went with this size pump? Surely it can't be a "one size fits all" type of thing.

Something I learned about oxygenation while researching this is that the actual bubbles going through the water don't really transfer that much O2 to the solution due to surface tension, it is when they break the surface of the water at the top of the bucket and mix the solution with the root zone air where most of the O2 transfer occurs. Knowing this, I made the feed lines as high as possible, so in addition to the bubble diffusers there is the "waterfall" effect which also aerates the solution...nice to have if your air pump fails IMO.

Ok, so this is why you have top runs and lower runs. This makes sense. So I can eliminate the need for upper pvc runs, and use drip feed hose powered from an inline danner mag pump to acheive the waterfall effect. Are these Danner Mag pumps reliable? I would like to get one of those to power this thing, and if I can find one, an air pump to power the air stones in all 4 buckets.

Yes the top lines are the "fill" lines, but they don't really fill anything, they are just circulating the nutrient solution. The buckets are always full of water as this is a DWC system.
Ok, yes. I get it now. Thanks

I don't see a problem with reversing the flow and making it into a F&D setup, but I would leave the feed lines and in turn they would turn into the drain lines/hieght controllers (kind of like a ebb and flow fitting, the water will rise until it gets to the feed lines then drain back into the control bucket. could just plug the pump into a timer for the feeding (wet) time...I've always been a fan of DWC so I really don't know much about F&D.

Oh, sorry for the confusion. When I used the words "Flood and Drain", I was specifically speaking of the flow of things, the route the water travels when loaded with the nutes, emptying tanks, change outs, etc. I'm still learning to talk shop, as far as DWC goes. I plan to run DWC with a drip feeds coming from the return lines.

How often are you running your pump that moves your solution? I know usually people run their air-pumps for their air-stones 24/7. But, I've seen a video demonstration of the Under Current system by Current Culture H2O, and the user had his pump running at the time; either to show the flow of the solution/water, or this is how that particular system is operated. I'm assuming the constant recirculation of things is what makes this system what it is, and enables the user to easily manage stable pH and EC levels.

See, I'm trying to use this Waterfarm res and controller unit and I'm not sure if I should be running the main res on the same pvc line as the controller and buckets, keeping the solution in all tanks circulating. I'm assuming this is a must, yet I do not understand how to keep things from over flowing, when pumping water back into the main res stacked up on the controller, which is controlled by the float valve in the control tank.

Water would need to be removed from the controller, in order for the float valve to unlock and allow solution to come rushing into the controller by gravity, and on it's way to the buckets. I could get away without useing the larger reservoir, and just maintain the controller, but I wan't to cut out extra maintenance down the line.

If the pump is set up right before the main res, on the end of the return line, pulling water through the entire system from the control reservoir.... wouldn't this automatically lower the water level in the control res, forcing the "float valve seal" to unlock allowing water from the main res to enter the control tank by gravity?

But in order for everything to circulate, the pump would have to be on. But this could be on a timer couldn't it? Powering the drip feeds every so many minutes, and circulating the solution through out the entire system? Would this be enough to utlize the benefits of a recirculating system and maintain a ballanced pH and EC levels?

I'm trying to run the most efficient rig possible, while cutting down on as much energy consumption as possible.

Sorry for the novel. I feel I'm right on the verge of a breakthrough.

hydrolized · 08-29-2009, 05:04 PM

Quote:

Originally Posted by Dr. Funkenstein

How often are you running your pump that moves your solution? I know usually people run their air-pumps for their air-stones 24/7. But, I've seen a video demonstration of the Under Current system by Current Culture H2O, and the user had his pump running at the time; either to show the flow of the solution/water, or this is how that particular system is operated. I'm assuming the constant recirculation of things is what makes this system what it is, and enables the user to easily manage stable pH and EC levels.

The pump runs 24/7 circulating the solution. It could be on a timer, of course, but why turn off the waterfall effect if you don't have to..ya know. The pump in this system only uses 45w of power anyhow, and since a chiller has been installed inline, it must run 24/7 since it's pumping through the chiller. It's a magnetic drive and obviously external and not water cooled so it transfers very minimal heat to the solution. Yes I think a constantly circulating system will give the most stable pH and mixing effects. You asked in the beginning of this thread if there were any Cons to a recirc. system, and there are. The biggest one by far to me is spread of disease. If one plant gets pyth or algae, the rest will get it in short order if you don't take the right steps to stop it. Another Con is if you are not very good with PVC, you could have leaks that you normally wouldn't have with a simple system. The more parts/pipes you have, the more you have that can break/clog/you have to clean later. IMO the benefits and user friendliness that this system offers is a great trade off to the possible Cons.

See, I'm trying to use this Waterfarm res and controller unit and I'm not sure if I should be running the main res on the same pvc line as the controller and buckets, keeping the solution in all tanks circulating. I'm assuming this is a must, yet I do not understand how to keep things from over flowing, when pumping water back into the main res stacked up on the controller, which is controlled by the float valve in the control tank.

Water would need to be removed from the controller, in order for the float valve to unlock and allow solution to come rushing into the controller by gravity, and on it's way to the buckets. I could get away without using the larger reservoir, and just maintain the controller, but I want to cut out extra maintenance down the line.

If the pump is set up right before the main res, on the end of the return line, pulling water through the entire system from the control reservoir.... wouldn't this automatically lower the water level in the control res, forcing the "float valve seal" to unlock allowing water from the main res to enter the control tank by gravity?

But in order for everything to circulate, the pump would have to be on. But this could be on a timer couldn't it? Powering the drip feeds every so many minutes, and circulating the solution through out the entire system? Would this be enough to utilize the benefits of a recirculating system and maintain a balanced pH and EC levels?

I'm trying to run the most efficient rig possible, while cutting down on as much energy consumption as possible.

Sorry for the novel. I feel I'm right on the verge of a breakthrough.

It's alright...all these pipes and pumps and floats get confusing. Is there a reason why you want to go with drippers and not just feeds into the buckets like in the system I pictured? If you want to go with drippers, to make things easier I would just plumb the system like in the picture, but instead of going into each bucket just cap off the PVC right before the bucket and install a 1/4" quick connect and push the drip tubing into that, wrap about the plant stem base, and your done.

As for the controller, I think you are over thinking things. I'm not sure how the waterfarm system is set up, but I will try and put the names of that and this system together so we understand each other. Each of the 8 buckets in the room is like the individual waterfarms. The pump bucket outside the room is like the control bucket. When this system is filled, you put all of your solution (30-40gallons in this case) into that control bucket, and it will flow into all the room buckets through the drain lines.. whatever water level you make the control bucket, all the room buckets will have that same water level, since they are all connected by the drain pipes. When you turn on the pump, it takes water from the control bucket and pumps it into all 8 room buckets...the level doesn't change though because while the pump is pumping water out, it is returning through the drains back to the control bucket.

Like you said, when the plants drink and the level drops, you can just make up a 5 gal bucket of solution and pour it into the control bucket to bring the level in all buckets back to where you want it.

If you want it REALLY lazy-style, you will install the float valve in the control bucket (pump bucket)...you will raise a larger container (55gal drum lets say) above the level of the bucket for gravity drain, and attach a line from the bottom edge of the drum to the float valve on the control bucket. Now, when your solution level drops in your system, the float valve will open and the solution will flow from the drum into the control bucket, topping off the system for you, instead of you having to make up a bucket every few days.

So, if you built the exact system I did, all you would need extra is a float valve and a large container to hold the top off solution.

One thing to think about though, is that when your starting with new strains or learning the pH and EC curve of your strains, your going to want to watch the EC go up or down, to tell weather your plants need more or less food...if you have a pre mixed control bucket topping the system off automatically, you won't be able to monitor this. I could explain this further if you would like.

Forgot to add about the air pump, it doesn't really matter how many buckets you have, the calculation is done by the number of gallons in your system. Say you have 5 8 gallon buckets in your system...4 plant buckets and one control...your not going to have the whole 8 gallons in each one as they would overflow so lets say your going to have 6 gallons in each. So now we have 5 buckets x 6 gallons = 30 gallons total. Now you want 2000cc (2L) per minute, per gallon of water. So 30g x 2L= 60 Liters/min (or 60,000cc/min). If the pumps your looking at are rated in GPH which some are, then you will have 60L/min x 60 minutes = 3600 Liters per hour There are 3.785 liters per gallon, so 3600/3.785 = 951 GPH.

Dr. Funkenstein · 08-29-2009, 06:16 PM

Quote:

Originally Posted by hydrolized

Forgot to add about the air pump, it doesn't really matter how many buckets you have, the calculation is done by the number of gallons in your system. Say you have 5 8 gallon buckets in your system...4 plant buckets and one control...your not going to have the whole 8 gallons in each one as they would overflow so lets say your going to have 6 gallons in each. So now we have 5 buckets x 6 gallons = 30 gallons total. Now you want 2000cc (2L) per minute, per gallon of water. So 30g x 2L= 60 Liters/min (or 60,000cc/min). If the pumps your looking at are rated in GPH which some are, then you will have 60L/min x 60 minutes = 3600 Liters per hour There are 3.785 liters per gallon, so 3600/3.785 = 951 GPH.

About the disease issue. Blazeoneup put together a tut at icmag.com and included shut off valves between each bucket to quarantine the diseased plant. I was thinkin this may be an option. Now that you bring it up, it seems its obviously a problem with a constant circulation system as well.

As far as why I chose hose feeds, or drippers, is because I wanted to eliminate any excess large sized holes that werent needed to be installed in the side of the bucket. I figured I could just run some hoses from the return line, since pressure is already moving that way.

And finally, the float valve idea. This is what I was going for. It's exactly how the Waterfarm works. Im just trying to understand how I will forcefully, by pump, add water to the main res, which sits on top of the control tank, and trigger the float valve. I cant wait for the control to evaporate

the pump would over flow the main res on top by that time. This is what must be done to have all tanks, buckets recirculating.

So would the pull of the pump, reduce the level of the control tank enough to allow for more water to be filled from the float valve/main tank res up top? To create a closed cycle of water flow?

hydrolized · 08-29-2009, 09:07 PM

Quote:

Originally Posted by Dr. Funkenstein

About the disease issue. Blazeoneup put together a tut at icmag.com and included shut off valves between each bucket to quarantine the diseased plant. I was thinkin this may be an option. Now that you bring it up, it seems its obviously a problem with a constant circulation system as well.

Valves would work. I actually thought about putting 2" valves in between each bucket on the drain side also, but when I saw they were $20 I opted not too. The way I have the buckets plumbed won't allow isolation anyways since the buckets drain "through" each other, if you get what I'm saying..so I would only be able to isolate the three farthest to the right. When it comes to running these systems and reaping the benifits and ease of use, prevention of disease and problems is key, not trying to fix things after you have a problem...Benificial Bacteria and proper enviromental and root zone condtions should be verified with a week or so of dry running before plants are put in IMO. I understand why one would wish for isolation valves in case "shit happens" though.

As far as why I chose hose feeds, or drippers, is because I wanted to eliminate any excess large sized holes that werent needed to be installed in the side of the bucket. I figured I could just run some hoses from the return line, since pressure is already moving that way.

I'm confused on what your calling the return line...do you mean the smaller 3/4" "feed" line in the system I posted? if that's the case then yes that would work just fine.

And finally, the float valve idea. This is what I was going for. It's exactly how the Waterfarm works. Im just trying to understand how I will forcefully, by pump, add water to the main res, which sits on top of the control tank, and trigger the float valve. I cant wait for the control to evaporate

the pump would over flow the main res on top by that time. This is what must be done to have all tanks, buckets recirculating.

So would the pull of the pump, reduce the level of the control tank enough to allow for more water to be filled from the float valve/main tank res up top? To create a closed cycle of water flow?

I think your still confused on this part, or I'm not understanding you correctly. When the system I designed is full, then the pump is turned on, the water level in the control bucket doesn't change. As soon as the water is pulled from the bucket and pumped out to the plant buckets, it returns via the drains at the bottom. The only time the large holding tank would let more water in would be when the plants drink enough solution to lower the float valve in the control bucket enough to open it. So in short no, the control bucket level does not change once the pump is turned on...at least in the system I posted and havebeen describing...the feeder hose off of the feed pressure side piping modification you want to run would not affect the mechanics of the system so it would function the same way.

Dr. Funkenstein · 08-29-2009, 11:24 PM

You are correct. The water level in the control bucket in your system does not change until evaporation occurs. I understand this. But with the use of a top off res, incorporated with the control tank unit, things are different. As Daltron point's out in his Bio-Bucket construction thread, the pump runs 24/7 circulating the water thruought the entire system leaving no dead zones where bad bacteria can develop.

So if one were to use a "top off" reservoir with a control tank, they must also incorporate this tank in with the circulation route. To keep all tanks circulating, at the same pH and EC levels. Without doing this, the "top off" reservoir would have a different pH and EC level from the rest of the system. Yet, it is slightly more difficult considering the "top off" tank and control tank combo seem to work on gravity by the use of a float valve.

In order for the "top off" res to fill the control tank, fluid from the control tank must exchange out to trigger the float valve, or evaporate (which wont happen as fast as the pump will fill the top off res) letting in new water from the "top off" reservoir from above.

Here are some plans I drew up, so you can see what I have in mind and you can advise where I'm going wrong or what I'm doing right:

hydrolized · 08-30-2009, 09:21 AM

It also will change when the plants drink water, as all the buckets are connected. I see now what you are saying about going through the holding tank.

I never thought about needing circulation to keep bacteria from forming, but I think if you just put an airstone in the holding tank to keep the DO up, it would be fine. I don't think recirculating through the holding tank would prevent anything at all. The GH system shows this, that 8 gallon holding tank doesn't even have a airstone in it and seems to work good enough for GH to put their name on it...

If you are worried about it, I would just build your system without the holding tank for the first grow, then when you figure out the max number of gallons your plants will drink in say, 5 days, just make the holding tank just big enough to last for a week..that way you will be putting fresh solution in it every few days to a week, and wouldn't have to worry about bacteria in the first place.

Dr. Funkenstein · 08-30-2009, 01:58 PM

Quote:

Originally Posted by hydrolized

It also will change when the plants drink water, as all the buckets are connected. I see now what you are saying about going through the holding tank.

I never thought about needing circulation to keep bacteria from forming, but I think if you just put an airstone in the holding tank to keep the DO up, it would be fine. I don't think recirculating through the holding tank would prevent anything at all. The GH system shows this, that 8 gallon holding tank doesn't even have a airstone in it and seems to work good enough for GH to put their name on it...

GH is a brand name and all, but a lot of people put their names on products that do not work. Users of the GH Waterfarm unit have told me that pH levels are a bitch to control, as each individual bucket, the control tank, and main reservoir end up having its own pH to contend to. I imagine if GH mentioned this in their sales ad, many people would not bother purchasing this unit. As it only presents more problems down the road, especially as a beginner. The only reason why I was considering purchasing this controller/tank is because it has a small foot print and would eliminate the need for me to go hunting specific sized totes and building it, on top of building my buckets.

If you are worried about it, I would just build your system without the holding tank for the first grow, then when you figure out the max number of gallons your plants will drink in say, 5 days, just make the holding tank just big enough to last for a week..that way you will be putting fresh solution in it every few days to a week, and wouldn't have to worry about bacteria in the first place.

The purpose of doing all this homework, is to acheive the simplest most maintenance free system possible. I would like to measure twice, cut once if you catch my drift. If I'm already purchasing the unit for my control tank, the main tank will come with it, so I might as well modify things right away.

I think that if the pump removed enough water from the control tank, it would release the float valve to allow more water to flood the control tank from the top off reservoir. Creating a constant cycle. I'm just concerned that the constant flow of things, and the larger top off reservoir, may flood the individual grow modules. Which may or may not happen, depending on if the pump can pull water from the control tank fast enough. Plus the feed on the control tank will be a 2" PVC pipe, and the feed of the top off reservoir/control tank is just a hose, which would slow down the refilling of the top off reservoir I imagine.

If the control tank feed is attached to a float valve, that means the solution should be controlled as it enters the tank, right? It won't simply come rushing in because the float valve is unlocked, would it?

I may just extend the elbow feed that runs after the mag pump and run one to the control tank. So there will be a feed for both reservoirs, controlled by a cut off valves. I will also add an extra air stone to the top off reservoir to see if that can keep things level with the rest of the system. If not, the extra feed will already be installed to feed top off reservoir. This, I imagine will help me deal with heavy feeding plants and light eaters.

Also, What is an MPT? Thanks for the help.

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