nutrient wise, you can't plant too many. you won't have the space. I grew 18 plants with a 30L rez last year (approx 8 gal)though not with DWC. you rez will be approximately 53L.
Spacing for plant size and light availability will probably dictate how many you can place. I set mine at approximately 8" x 12" spacing, and the inner plants were still slow to come along. Of course I grow outdoors. If you're using HID's, you may be able to plant denser, but I wouldn't push more that 8" x 8"
Of course, freqency of adding nutrient concentrate and / or water is also a concern. the more plants you have, the more water they consume AND the more rez space their roots occupy. thus more plants means less volume for water + more water uptake = more often adding liquid.
But again, your plant spacing will probably dictate how many you can plant. what are the dimension of the lid?

Thanks grizz

Where I can actually cut holes for my pots is 12"x18".
I thought about putting 1 in each corner. Do you think 4 plants is too many. Right now I have just one plant in a 3gal. bucket using 1.5 gal of solution and it does great without adding very often. So I guess 4 plants x 1.5 gal would give me 6 gal. of solution which is about 1/2 full in the rubbermaid. These would be inside under combo of hps and flourescents.

Thanks, Tod

I often see people just lumping all "peppers" together, or in other words not actually differentiating between varieties. How comes and do you guys generally mean bell peppers when calling them peppers?

I mean I perhaps see this point very differently as a matter of facts that I have been growing a multitude of varieties (hot and sweet) with very different growing habits, ranging from less than 5 inches up to 5 foot and taller.

But to answer the actual question, yes depending on variety 4 or even 5 (one more in the middle). I believe the other 4 wouldn't mind one more 'Bro' at the table ;-)

Ah yes Lucas, I hadn't considered multiple varieties. I just assumed they were all one type.
Tod,
I would probably do two rows of 3.

I have grown 2 varieties of peppers in a 14 gallon rubbermaid. Cayenne and sweet bells. I made it an "aeroponic" one from the book "How To Hydroponics" a few years ago. I quickly learned that the 4 plants I had was 2 plants too many. Here is why:

1) Room. As mentioned, the peppers need room. Unless you plan to be very strict about pruning, that is. Some people prune to just 2 "vines" (main stems, not really vines). That produces bigger, but less fruit. If you are selling them, bigger is better. If you are eating them, smaller fruit and more of them is better in my opinion. Quality seems equal to me. Anyway, it matters because if you prune like crazy you might fit more. Otherwise, the pepper plants can get very huge really quick.
2) Again, it has to do with size, but this time its weight. Unless you plan to support the weight from above, more than 2 plants will weigh too much when mature for that flimsy little lid to handle. I found that out the hard way when one of my plants fell through the hole because the constant weight stretched the hole out.
3) Have you considered how you will change the solution later? 4 plants will make a humongous mass of roots in the rez. It's inconvenient when you go to change out the solution. Even 2 plants can produce a huge root mass after a time. You will need to use a pump to clean the rez out or have another rez waiting ready. The problem with changing rez's is, again, the weight of the plants on that flimsy lid and the fact that they don't tend to stay still. The problem with the pump is the root mass.

If you support the plants from above and train them outward from the container, 4 plants might be perfectly fine. Personally, the whole thing taught me one thing for certain. Grow peppers in sturdy 5 gallon buckets and store your hydro stuff in the rubbermaid.

I had three plants in a 15 gallon tub. One on each end on one side, the other in the middle of the opposite side.

I now have three Calabrese Broccoli plants in it!

Mike

I am growing four varieties in my raised beds this year, 2 hot, 2 sweet. They are just main stem and leaves at the moment. I was wondering if they will branch off so that I can clone them like I do with my toms, as they take long to start from seed, but Joe just answered my question. Is there anything special I should know RE: cloning peppers? Thanks for the pruning tips Joe.
Ken

We still don't know what kind of peppers they actually are. I don't prune hot peppers at all, unless they are Capsicum baccatum or bigger sized pod type varieties.

The spacing and the respective growing habit really depends on type as well. Many hot peppers that are "classically" grown in the pepper community grow actually at a slow rate, especially from seedling to a foot tall. After that they accelerate.

A 14 gal. rubbermaid tub is not really big, and some varieties may grow too big for the reservoir size with only a single or two plants.

I once started 6 (or was it 5) plants with this type of setup and let the plants grow until space and nutrient capacity was kinda exhausted. After that I transplanted 3 of them an left only 2 in it. This kind of plan may also apply here, start with 6 and transplant a few in 2 moths time or so into the "next" setup.

PS: @hardclay7a: branching habit of peppers also varies widely, some varieties like Tepin or even some C. Frutescens can grow 1 meter (3'4") until they are branching. Huge bell pepper varieties may also grow much taller than expected before they think of branching. Some other varieties may branch unexpectedly early. It's also a mater of time vs. growing rate, - they'll probably branch at some moment in time no matter how high they are then. Same for blooming, if time is up (around 2-3 month) they'll go to blooming, no matter how mature or tall they are. Cloning peppers isn't as easy as with tomatoes, - if your technique is good and conditions are right it may work just fine, but if it's too cool or too hot, not humid enough - they may be problematic with rooting before getting week. Well here I am partially talking about my tropical and local experiences over the years and also reflecting what other growers report from around the world.

Yea I guess I should have clarified my question. I am talking sweet bell peppers. Part of the reason I'm asking is that I would like to get away from checking and adjusting nutes in 3 different containers. My air pump is large enough to power plenty of buckets, but with dwc is there a way to interconnect them so that I'm only checking one reservoir?
Thanks for the replies, that's why this forum is so great, there's always ideas or suggestions that I would have never thought of.

Thanks, Tod

Good thought Tod,

As after a while a few setups may indeed accumulate and you would sooner or later get tired of taking care of them individually. I am actually facing a similar problem, so to speak and have already figured out something that is based on what I saw at some MJ-grower site a while back.

What I was planning but haven't got the time to take care of practically, is a so called RDWC system. Not sure if this has become the official term everywhere since, but it stands for Recycled Deep Water Culture. It's based on a bigger (generous) main reservoir that provides nutrients for a few buckets, and/or for a few systems if it applies. You simply have to install a smaller inlet tube to each setup or bucket that provides them with a fresh nutrient flow and (what is more tricky) a 1-2" overflow and collecting outlet tube. The pump feeds all the buckets or reservoirs and the outlet simply evacuates the nutrient flow back to the main reservoir, as soon as it reaches the overflow level.

If seeing the basic principle graphically it becomes more than obvious. I must have some 3D render hanging around that I made some rainy afternoon, if you like I can dig it out and post it here.

Cheers
Lucas

Thanks Lucas,

Yea there are some things I can picture in my head, but this isn't one of them. A picture is worth a 1,000 words. If you get the time that would be great if you could post it.

Thanks, Tod

It should be pretty self-explanatory now.
The inlet can be anything from 1/4" PVC (or somewhat bigger) to a micro tube. No need to make anything watertight, just drill a hole and stick it in or let it glide down from the top.

As for the outlet and return you have to strictly make it water tight somehow, otherwise it would be leaking with climbing water level. With another idea I wanted to have a double outlet, connected with a "T" - simply to make the PVC tube sit more stably. A single tube is more prone to movements and tension. Hope you can picture that part without a graphic illustration.

The outlet's (overflow) hight is variable and can be at different hight(s). Either the same kind of bucket or various setups could be connected in such ways, in case with minor modifications, though. You only need to respect the laws of gravity.

PS; this is a simple 3D and it's not about good taste but only that "colorful" for illustration purposes. ;-)

Hope this helps,
Lucas

There are two problems I immediately see with your model Lucas.
Once the buckets are full (to the outlet level), the lower areas of the bucket will not get recirculated. Water will come in the top, laminar flow across and straight out the overflow tube. you'll end up with oxygen depletion in the lower levels of the bucket. a simple solution to help would be to extend the inlet line to the bottom of the bucket forcing the water to circulate through the volume.
changing out the nutrients will be a nightmare as you'll have to detach each bucket and drain it individually.

A more simple solution is to have your drains set to expel from the bottom of the bucket (or out the side at the bottom) and set your main reservoir such the the max fill line is the same as the max water level you want in each bucket. That way the water dumping into the top will circulate through the volume in order to exit the bottom of the buckets. Also, once it's time for a nutrient change, simply drain the reservoir and the water volume in the buckets will drop also.

Well this is not a technically mature model but a draft. And yes it's open for discussion.

The first "problem" isn't actually a problem, I was also thinking of extending the inlet, when doing the post. That's easily done. Although I wasn't afraid of lack of oxygen, the nutrients are recirculated anyway, depending on the stream or the inlet (sprayer?).

As for changing the nutrients, it would not be more of a nightmare as with any bubbler without small outlet at the bottom. A smaller outlet line at the bottom (either connected to all or with each bucket) with a main faucet would indeed be a good idea and the best solution here.

If the main outlet would be at the bottom (of any reservoir or bucket) it couldn't hold any water level, could it? ;-)

I think with both modifications it will just work fine.
Either a (multiple) bucket system or connected reservoirs would call for slightly different modifictions or versions, though.

And Voil

Once more, the logic and the point of the"top-outlet" is, that you only have to control (cycle and/or dose) the inlet stream, that's it, gravity does the rest.
You may modify the actual height to your needs of course.
I have added a secondary outlet line at the bottom for easy nutrient change. This would indeed be indicated if a new setup would be build, but it adds one more "week point" that could leak. If one intends to connect a couple of reservoirs with such system, they may already have their own outlet or faucet, or whatever facilitates nutrient change. In that case it would be added to such "interconnected" system, a flexible hose would come handy.

I agree that less holes = less leak potential. I'm just suggesting the high / overflow pipe is not needed. (just the low outlet) Since the system is not airtight, air pressure will keep the water level of all the buckets and the reservoir at the same height. ((an analogy: connect any two buckets together with a pipe at the bottom. fill up just one with water and they'll both fill to the same height.))
This also allows you to only drain from one central location as opposed to multiple bucket locations. If you did it this way, you would NOT want to extend the inlet pipe to the bottom but stop the pipe near the top.
Done this way, a pump is not actually required to fill all the buckets, it is merely there to circulate the nutrients through the system. This way all modifications to you nutrients can be done at the main reservoir then circulated to all the buckets.
Here's my rough sketch of what I am saying:

Well as I can see, these are two completely different ideas and concepts, both plausible but with different rules and as well with different goals in mind, in fact exploiting gravity in opposite ways. Your buckets are indeed all at the same level and hence the outlet could be anywhere in between the bottom and the upper water level of the main reservoir.

I guess that a picture of the whole system makes the particular concept and the actual advantage of the higher outlet finally clear. Actually there is one thing I need to add; obviously there is a certain height difference needed between buckets and main reservoir with this concept. This can be realized by elevating the buckets or digging the main reservoir (partially) in. Depending on terrain or other particularities, a combination of both would most likely be the first choice (mine anyway). Elevating the buckets somewhat and digging the reservoir at least half in - or place it at a lower elevation, if infrastructure/landscape permits.

The concept of the shown system is diametrically opposed of what grizzman proposes here (figure of speech), and yet very close to the original RDWC -not actually invented or thought out by me. The only thing I've actually done here is simplifying it, as most other systems I have seen had complicated distribution systems for the inlet with lots of tubing and pressure regulation. If you simply use an adequate pump and experiment a bit and modify the diameter of the outlets accordingly, all of that isn't necessary.

The advantages of this system are like follows;

1- you have a real constant flow and unhindered nutrient exchange trough the bucket as there is no outside pressure to the outlets or interfering flow from the other buckets.

2- with the hight difference between buckets and main reservoir (sorry for that - which I thought obvious but didn't clearly point out earlier) you have a true back flow through the outlet tube system and most importantly: thus permanent oxygenation inside the reservoir from the dropping back flow. This is the most important feature and advantage, actually the base- and bottom line of the whole concept.

3- your buckets are only supplied with indeed oxygenated water from the reservoir only. Contrary to the "other system", there is no exchange or "interference" of less oxygenated nutrient between buckets.

4- the water level in each bucket doesn't alter with the water level in the main reservoir or the "general level" at all, but keeps constant at any time (as long as it is supplied by the inlet regularly). It is in fact dictated by the location/hight/level of the main and bigger outlet only. PS: This level is fix with this design but one simple 90° fitting added inside the bucket enables you to regulate the level from inside the bucket by around ± 3-4 inches (still independently of the main reservoir level).

5- If, as actually asked, several systems (actually their reservoirs) have to be interconnected, they would very likely be of different kind, hight or require distinct water levels - perhaps could even be located at a different hight or field level. With the "original system", that wouldn't even be a problem, as the hight of the outlet can differ from reservoir to reservoir (in certain limits) and the whole system would still work as usual.

I think you misinterpreted my sketch. This section should clarify:

So you can see "interfering flow from the other buckets" does not exist and therefore "no exchange or "interference" of less oxygenated nutrient between bucket" exists either.


As I mentioned earlier, what I proposed allows everything to be maintained in the reservoir. I was including aeration in that.
Of course varying the depth in the buckets is just as easy in what I proposed. Simply raise or lower the buckets as needed.

Also, Lucas' system still forces you to put extra holes in your buckets to drain them.

Lucas system PROS:
allows for a height differential between buckets and reservoir.

CONS:
more holes for potential leaks
more complex to set up
your buckets must be set higher than rez for aeration
less convenient to change nutrients.

What I suggested are pretty much the converse of that.

Well I have- or haven't misinterpreted your outlet system - I am not sure, because the first design seems to have an outlet of a much bigger diameter than the second.

Either way a outlet of a certain diameter would be necessary to evacuate as much nutrient as gets pumped in in each bucket through the inline. In fact the diameter of the outlet dictates how quickly the climbing level of each bucket can be equalized, otherwise your buckets will simply overflow in a short time. But if your inlet is delivering a very small quantity of nutrients only, that's some kind of limitation that I wouldn't want to have. Why would I want such limited flow and the resulting "performance" limitation of a system?

Everything is at the same water level an literally flooded and with low inlet pressure you'll have not much nutrient stream/movement because the only thing that gravity does here is equalizing a very slowly changing difference.

With a small outlet diameter (as shown at your last illustration), there will be literally no back flow (or whatever nutrient exchange) between buckets indeed, but there will not be much of a flow for my understanding of a RDWC system either.

I guess the little extra hole in my design for easy nutrient change isn't going to leave a leopard its favorite spot and the fine auto-oxygenation is worth setting the buckets higher or the reservoir lower. The later is anyway more common than an exceptional or fancy thing with most systems, as far as I see.

Thanks guys,

This is so interesting. It gives me lots of things to think about. One question for either system. Would a person only have to oxygenate the main reservoir?

Or would each bucket still have to be aerated? I see with Lucas' design the lower reservoir allows for a water fall effect thus aerating the reservoir, would that be adequate? With Grizzman's design you are getting the waterfall effect in each bucket correct? I could then just aerate the main reservoir right? Or would there be enough oxygen exchange through the water falling in the buckets?

I see advantages to both systems, but the main thing I want to accomplish is not checking and adjusting nutes in lots of different buckets and it looks like both designs would accomplish this.

Keep on discussing it though it's cool to see the different perspectives.

Thanks, Tod

Both designs/systems are working designs I believe and if you have the skill- and toolset (excuse my french) to nail one of those babes, you can nail the other as well... it's a matter of choice only as you wouldn't build both ;-)

About the drop down "waterfall effect" I can only tell that I use it successfully with a 8 channel 220 plant NFT system without any auxiliary oxygenation, as we speak. And yet the nutrient temperature is very high (30-34°C) due to air temps that went up to 40°C the past weeks, here in "summerly" Northern Thailand. This is indeed a clue that even with less dissolved oxygen capacity, it's replaced quickly enough. All commercial farms I have visited so far in the neighborhood also rely only on oxygenation from runback stream "waterfall effect".

PS: the extremely high nutrient temperatures I mention here are "off the record notes" based on what I call myself selective observations - and thus aren't to be understood as a recommendation from my side. Also, they are due to the fact that the NFT setup in question is a quickly build test unit and that there was no time to take any measures to insure adequate temps. But then again, if this was handled by the book and the situation was prevented from my side, I wouldn't have witnessed and realized this exceptional "upper limit" with nutrient temperatures. ;-)

Since you are using this system so successfully, could you please post a real life picture? I love seeing new systems in use.

What do you exactly mean, the NFT unit with dropping run back oxygenation?
Anyway, it's real but not really (a)live, it's more like from PVC and other synthetic materials. ;-)

trenhes;
you would need to aerate the main reservoir in my proposed design. I would not count of the water falling into each bucket to provide enough aeration.(though it may)
Joe;
I don't actually use this setup. I really prefer NFT for smallish plants and the DWC/Aero can to grow tomatoes.
If my Ligustrum cuttings take I may go this route to grow them however. But we'll have to wait until then.

So I'm thinking about Lucas' system (LS) versus my system (GS) and it occurred to me that with LS, if you ran the vertical pipe of the overflow inside the bucket instead of outside, it would be easier to adjust the bucket fluid level. Simply remove the inside pipe and replace with a longer or shorter piece.
Another consideration (and not related to the previous train of thought)is water pump size. with LS the minimum head required would be the height of the bucket plus the difference in height from the bottom of the bucket to the top of the reservoir. (assuming it is filled to the rim) with a maximum height adding the depth of the reservoir. in the GS, the max height is the depth of the bucket plus any additional depth from the bottom of the lowest bucket to the bottom on the reservoir.(in my mind 3"-4")Assuming 5 gallon buckets and a 50L rez, the GS max height would be something along the lines of 22" (18" of bucket + 4" raised above rez bottom) The LS minimum-max height would be something along the lines of 36" (18" bucket + 18" rez height) I call this a minimum-max because in all honesty you'd need some additional height to create your waterfall for aeration.
I only point this out because to maintain the same volumetric flow in both systems would take a larger pump in LS vs GS and larger pumps cost more.
As everyone seems to agree, both systems would probably work just fine so then cost is somewhat of a factor. Of course with LS, you don't need an air pump for aeration which you do need with GS. So then the question becomes does the difference in pump costs offset the cost of an airpump. Without actually designing and sizing things, I can't really say. Just food for thought.

Lucas: Yeah, sorry. I meant the NFT. And by "new" I mean new to me. I don't think I've ever seen your system and I'm thinking about trying NFT this year. I'm completely redoing most my stuff. Actually, this thread has given me some great ideas. Could you start a thread with pics of your systems?

For Joe:

NFT trough draining into reservoir. This rez holds 20L

Looking under the lid


It's a little low right now.

@grizzman,
About pump size and cost: considering the fact that the pump used/shown in the next picture has only a consumption of 50 Watt and is worth around 15US$ only, I am not really seeing it as a con nor a problem.

@Joe, without false modesty I guess I am doing a bit more than just trying NFT this year, I am actually designing, manufacturing and setting those up in different locations.

In fact, some of this is more recent and I need to use some discretion for several reasons. You can have a glimpse on them though.

Here are two similar but somewhat different designs and setups. 1. The one "in action" is the more "robust" test unit I was referring to earlier and it uses a new type of NFT channels that are manufactured here in Thailand. Those are actually a well working low cost version of the "traditional" channels seen from common manufacturers. They have also the advantage of easy access to roots and much easier cleaning, even between crop cycles.

2. Right upper corner: the actual design with complete frame for aphid net, shading cloth or plastic rain sheet.

PS: both design and setups were also preceded by numerous 3D renderings and simulations, before the "real thing" was build and eventually tested. Trust me, I also like and prefer the real thing taking shape in front of me, but drawings or 3D designing really reveal a lot and save expensive trial and error. This way of working becomes even more useful and effective, if the person who is designing in 3D simulation has got engineering practice with only a few previous setups, all the materials, actual requirements, etc.

All this is part of a bigger project and that's all I can reveal so far for now because of a Confidential Disclosure Agreement ;-)

Thanks guys.

Grizzman, I assume the foil is for root zone temp regulation. How much of a difference does it make or have you checked? Just curious.

Lucas, are the hoops for plant support or plastic/shade cloth? If not for support, then what do you use? It seems peppers would not support themselves too well in an NFT setup.

Now you guys really got me wanting to try out NFT.

Actually I use the foil to keep the inside of the tubes dark for algae control. But then again, maybe that is a heat problem?!? Anywho, it got pretty bad for awhile until I added the foil and put a lid on the rez.
Next year I will apply the foil before inserting the bet pots. I think it will go much smoother and look better that way.
I've never had problems due to nutrient temperatures (that I'm aware of) and two years ago we had record summer heats. I believe it was something 90 ~ 90°+ days breaking 3 digits a number of times. No ill effects then and I haven't been too concerned since.