I'm going to be building a DWC system using this basic design. Obviously with the drain tube at the bottom very little water is kept in each bucket. Is there a simple way I can modify this to be able to adjust the water level in each bucket?
Adjustable water level in DWC
- Thread starter Mr. Na$ty
- Start date
The water stays in the bucket, the drain is just there for when you need to drain the water out or take samples...You keep water in the bucket at all times.
here's my system:
http://img714.imageshack.us/img714/5327/p1040738smallerwlabels.jpg
I dont think so.....And even if you closed the drain partially it wouldnt be accurate and gravity would take the water into the next bucket in the series, right?
Besides why would you ever need to do that?
I'm not following I guess.
I would think the water height in the buckets would all be the same, even if there was a partially opened drain as gravity would flow the water to level.
I'll have to read up on it though, and don't see a need to have different height levels in different buckets...
Besides why would you ever need to do that?
I'm not following I guess.
I would think the water height in the buckets would all be the same, even if there was a partially opened drain as gravity would flow the water to level.
I'll have to read up on it though, and don't see a need to have different height levels in different buckets...
redi jedi
Well-Known Member
Yes, you can....
I would suggest reading the link the OP provided....
In the link, the system has four drain legs. Each leg has 3 buckets and one shutoff valve for the leg. So the level or depth of water in each leg could be different if needed.
The plastic shutoff valves listed in the link are not the ideal valve to use but they would work....
In a RDWC system, the level in the buckets is determined by the rate of feed vs the rate of drainage, its not a basic system and will take some tweaking to make it work properly.
A pump with adjustable flow rate would be handy but I don't think they exist. Your next best option would be to add a gate or globe valve to the discharge of the pump. That way you adjust both the feed rate and the drain rate.
I would suggest reading the link the OP provided....
In the link, the system has four drain legs. Each leg has 3 buckets and one shutoff valve for the leg. So the level or depth of water in each leg could be different if needed.
The plastic shutoff valves listed in the link are not the ideal valve to use but they would work....
In a RDWC system, the level in the buckets is determined by the rate of feed vs the rate of drainage, its not a basic system and will take some tweaking to make it work properly.
A pump with adjustable flow rate would be handy but I don't think they exist. Your next best option would be to add a gate or globe valve to the discharge of the pump. That way you adjust both the feed rate and the drain rate.
Mantis, by being able to adjust the water level in the buckets you can customize how much of your root mass is in the air. This is helpful in achieving the best growing conditions for any strain, as each one will have a slightly different preference for optimal growth. It is be no means necessary, but if there is a simple way to do it then why not?
Jedi, I've never used those valves before so I didn't know if they were adjustable or not. Essentially all I need is an adjustable valve at the bottom of each bucket to open or close when I want to adjust the water level. Then keep it partially open to where it has the same flow going out as it does coming in to maintain that level.
Jedi, I've never used those valves before so I didn't know if they were adjustable or not. Essentially all I need is an adjustable valve at the bottom of each bucket to open or close when I want to adjust the water level. Then keep it partially open to where it has the same flow going out as it does coming in to maintain that level.
You're right gravity is a bitch and would definitely keep a constant water level unless you had a one way drain valve. Then there is no way for water to be forced back up into other buckets it would just raise the level in your res by however much you drop a bucket. So as long as you had a one way drain with adjustable flow and room for expansion in your res it should work out
In order for it to work, I would think you would not only have to be able to adjust the drain valve, but also the fill as well.
If the fill and drains are different, it wouldnt work I don't think. So each leg would have to be a different FILL and DRAIN rate.. Correct? This would require fiddling with the drain valve and also the fill.
I haven't heard of different strains needing air on the roots...I thought that the roots were going to be in the nutrient solution to get oxygen from the bubbles...So that basically it didn't matter the water level as long as the roots were submerged in teh bubble bath getting oxygen.
Unless the difference in air was important, it doesn't seem worth it to me...a lot of work for an unknown outcome.
Even if air effects different strains differently, it would seem like unless you knew which strains to keep at which level, you would need to do a lot of research to figure out how much of an effect it had.
DO you have any references that show water level / air effects on the different strains? Sounds interesting.
If the fill and drains are different, it wouldnt work I don't think. So each leg would have to be a different FILL and DRAIN rate.. Correct? This would require fiddling with the drain valve and also the fill.
I haven't heard of different strains needing air on the roots...I thought that the roots were going to be in the nutrient solution to get oxygen from the bubbles...So that basically it didn't matter the water level as long as the roots were submerged in teh bubble bath getting oxygen.
Unless the difference in air was important, it doesn't seem worth it to me...a lot of work for an unknown outcome.
Even if air effects different strains differently, it would seem like unless you knew which strains to keep at which level, you would need to do a lot of research to figure out how much of an effect it had.
DO you have any references that show water level / air effects on the different strains? Sounds interesting.
I am really not sure. It seems to me (I could be wrong) that the main thing would be the level of water in the reservoir that would control the height of the water in the buckets. The flow rate seems like it would only control how many gallons/hour the water circulates.
The height of the water in the res SHOULD be the determining factor in the height of the water in any bucket connected to that res.
The simplest way I can think of if you absolutely had to have X number of buckets with different heights would be to just have another res. If you wanted 5 buckets at 1 inch below the net pots, and 5 buckets with 3 inches below...I personally would just have 2 Res's. That way all you need to do is control the height in the res, and thats it. No need for flow control etc...
Besides, if the reason is that they are different strains...They will probably need different nute levels and respond PH differently etc...etc...etc.. So having 2 seperate res's makes sense.
Thats just me tho, I like to keep stuff simple.
You are right. Like I said this isn't at all necessary, it' just something I was interested in trying out. If all you are going to do is try and disprove my idea then please stop posting. However, if you want to help me work this out and come up with ideas I would appreciate it. As I said before as long as the drain valve is only a one way valve then the water level in the res wouldn't effect the water level in the buckets because the flow going in is regulated by the pump which is pumping at a constant rate regardless of how much water is in the res. And water can't be pushed back up through the drain since the one way drain is only allowing water to exit the bucket at the same rate it is being pumped in.
I am not disproving (or trying to) your idea, I was asking questions and trying to help you. You are the one who said the reason for different water levels was "different strains." That is why I suggested two different reservoirs, as it makes logical sense to me. Seems like two different strains would need different nutes too. I. All I was doing is trying to help, I think you are making things way too complicated.I have never seen anyone write about different air levels for different strains, which is why I asked you for a reference or link to where you got your info...I truly am curious....If it doesn't affect anything, well, then it seems like a lot for work for nothing....Again, not trying to disprove anything, trying to find out if anyone else has researched this. I hope you succeed in all your endeavors / research.
redi jedi
Well-Known Member
First of all...theres no such thing as a one way drain valve. Any valve that flows in one direction only is called a check valve and is intended to prevent backflow. You need valve(s) that can meter flow like a gate or globe valve...like the valves you find under your sink or running to your toilet or the one your garden hose is attached too.
To prevent water draining to the res from refilling your buckets (backflow). You will need to keep the water level in the buckets higher than in the res. adding a check valve here won't work. The taller the water column, the greater the pressure at the bottom of the column. If the res has a greater depth of water than the buckets, the water trying to drain to the res won't be able to overcome the pressure or weight of the water already in the res.
Those plastic shutoff valves (in the link) are intended to be open or closed and may leak if left in any position in between. They also might not be able to give you the contol of flow you will need.
The easiest way to build a RDWC is to place the drains at the level you desire. For example...instead of having the drain fitting at the bottom of the bucket, place it about half way up or use 2" pvc coming up through the bottom of the bucket. The height of pvc pipe will be the point the water will begin to drain. By adjusting how far the pipe goes up into the bucket, you can adjust your water level.
These two methods are easier to build...I should say easier to make work...but once its done you will loose the ability to adjust the water level without performing some surgery on your system...good luck with your project, hoping you can bring it to life...
To prevent water draining to the res from refilling your buckets (backflow). You will need to keep the water level in the buckets higher than in the res. adding a check valve here won't work. The taller the water column, the greater the pressure at the bottom of the column. If the res has a greater depth of water than the buckets, the water trying to drain to the res won't be able to overcome the pressure or weight of the water already in the res.
Those plastic shutoff valves (in the link) are intended to be open or closed and may leak if left in any position in between. They also might not be able to give you the contol of flow you will need.
The easiest way to build a RDWC is to place the drains at the level you desire. For example...instead of having the drain fitting at the bottom of the bucket, place it about half way up or use 2" pvc coming up through the bottom of the bucket. The height of pvc pipe will be the point the water will begin to drain. By adjusting how far the pipe goes up into the bucket, you can adjust your water level.
These two methods are easier to build...I should say easier to make work...but once its done you will loose the ability to adjust the water level without performing some surgery on your system...good luck with your project, hoping you can bring it to life...
redi jedi
Well-Known Member
No, this valve is like a regulator you would find on a gas cylinder. WAY overkill for what you need...besides, that valve is probably in thousands of dollars.
Thanks guys. I found a couple things online today I'm gonna research a little more. If I find anything that works I will definitely post up some pics. I know different strains would need different nutes, etc mantis and you're right two res's would be the way to go for that. I wasn't talking about growing different strains in the same system but by being able to control the level in each bucket you can have each one set different and see how it effects growth of the individual plants of a same strain, and ultimately find the best level for that strain.
If you do end up doing that kind of research, make a huge post about it....It would be very fascinating......Like if you could have 6 plants..One with the water level up at the level of the pot, then like 1 inch down, 2 inches down.....up to 5 inches down. Or maybe do increments of 1.5 or whatever. Would be a ton of work but very interesting. Post some pics when it happens!