Plumbing My 20' x 40' Greenhouse

[Jonathan Hall]

Hey everyone, thought I would share my current plan of the system I am building.

Things are progressing nicely and more or less have this all figured out. However, I always like constructive criticism and maybe a new idea or two that I just failed to see.

What I am sharing with you is the floor plan for my 20 foot x 40 foot greenhouse. Specifically the plumbing map. If you can wrap your head around my amateur drafting / drawing skills and see something that I could do different or better by all means let me know.

Pump I am planning on is an Danner MD24. This should do about 1446 GPH at a 6 foot head. Not completely sure what my actual head will be, but I don't think it will exceed that.

Before I post the link to the photo of the design I will walk you through the obstacle course.

1. Water is Pumped from the final DWC/Raft bed and up into a X - Split that feeds four IBC fish tanks. Each tank is not directly linked to eachother (there are four of them)
2. Water gravity feeds over to a swirl filter of DIY design.
3. Water gravity feeds down the pipe and to another X. Which dumps in to Ebb/Flow Media beds.
4. Media beds drain in to a sump that is slightly higher than what I expect the DWC beds to be.
5. Gravity feeds leveled with the first DWC/Raft bed. 
6. Gravity continues to wind thru the beds until it reached the pump and the cycle is repeated.

You can see this graphically at the following link - click on it to enlarge;

Greenhouse Floorplan

Love to hear your thoughts and improvements. Its a work in progress.

[Jonathan Kadish NYC AA Chair]

A simple graphic and description of a system this big without the rest of the story of what you want to grow, how much and for what purpose is nearly impossible to even consider. A system of this size takes fair amount of engineering - if you want it to work optimally. Given how much money this will cost and how many things you will try that don't work, it would do you much good to study systems that are proven.  Study the UVI system which has 30 years of development behind it and is public knowledge, rather than reinvent the aquaponics wheel.

[TCLynx]

Well they are only talking about something on the order of 800-1000 gallons worth of fish tank total.  Not an extreme feat of engineering.  For a "first system" I admit it may be a bit over the top for the average first time system builder.  But my "first big system" probably neared comparable to that scale.

However, I must admit, I made plenty of mistakes on my first big system.

Make sure you put in plenty big plumbing from those 4 fish tanks.  In general go big on all your gravity plumbing.  It is generally far easier to make it smaller later but if you don't put in big enough to begin with, you will be sorry.

I don't know much about Raft aquaponics but I would recommend plenty of air if you want good plant growth.  My media bed aquaponics has always done far better than my raft attempts or my NFT attempts.

[Jonathan Hall]

Thanks JK. You are right. There is much more to this and perhaps I should write it down a little better. Bored at work and just trying to spark some conversation.

I am very much aware of the engineering that will be involved and costs associated. Luckily many of the big ones are all taken care of. The rest is fun. Like inventing a fun oblong shaped "wheel". I like to think of this as one big recycling project. Engineering second hand crap, into an Aquaponics system, as much as possible.

TC - They are the larger sized IBC's so it will be about 1100 gallons. I think I will tend to agree that this is not an extreme feat of engineering. There will be some very large PVC going on in the sump area... Wet Dry Filter, Degassing area, Kaldness Filter. The possibilities are endless, and all within reason to build. I want to stock a decent density so we will see how it goes.

O. Aureus Tilapia and Channel cats will be the primary workhorses of the system. Luckily a local college has a nice Aquaculture program. So sourcing will be affordable and close by (no shipping).

In the raft system, I also do intend to have a lot of air. To be exact, air stones every four feet. Now I know I am bending the wheel again here but I am also going to throw in some Prawn. Buy them locally live so I figured what the heck. Don't think they will be getting fed much, perhaps I will throw in a few BSF every once in a while just to see what happens, but from what I understand they don't really need it. Obviously, this will take some optimization.

Maybe we can do a before and after picture to end this off. Well the before anyways... The greenhouse that I am reclaiming to find new life and use. Its all taken down and moved to its new home now. However, just the stakes are in the ground at the moment. So the cleaner version later.

[Jonathan Kadish NYC AA Chair]

Oh Sweet! that is a nice thing to start with. So are you going small scale commercial or just for your family? Will you grow many variety of plants? The engineering I speak of is blowers, lighting (you look northern), heating , pipe sizing ect. Since you have your aquaculture connection they will have a lot of answers to those problems. Your system is a hybrid with media bed as your secondary filter which won't support heavy stocking rates as nutrients will become too concentrated there. You also run the risk of anaerobic zones in the media bed if sludge builds up. Up to 50% of the food you feed the fish becomes solids that you have to remove from the system... 2 pounds of food and you have 1 pound of sludge to deal with. The swirl filter will only get the big chunks but nothing in the water column so you may need another tank with bird netting in it to get more of the fine solids

[Jonathan Hall]

My family mostly however I think there may be more than we will be able to eat. I am expecting to donate a lot to some churches who do lunch programs etc. in my area. Maybe even sell some who knows.

Variety of what I grow is going to be key. Lots of lettuce, corn, bell peppers and many more. One special addition will be a Goji bush. If that works well, probably will grow a lot of them. Kids love them when dried like raisins and I can store them up for a rainy day.

Have a large exhaust fan that came with the greenhouse for when its sealed up. For heating, will be using a gas garage heater. On the wishful thinking side, a rocket stove with a concrete exhaust(heated pad) that the fish tanks sit on. Ultimately, if that fails will install a boiler system so I can be more sustainable and gas independent.

To deal with the sludge, I will be adding my red worms to the media. This should help some of that sludge get processed. As well as get aerated as they munch down on that delicious anaerobic bacteria. So will keep an it and see how long it does need cleaned.

Daphnia will also be added to the tank, who will hopefully hang out in the sumps a bit to keep it clean. I think the prawns may even like them?

The swirl filter right off the fish tank was there to hopefully grab some of that sludge ahead of time as well. The sump is one of the worst features of that drawing of mine ;). Once it leaves the media beds it will fall to a chain of large rubbermaid storage bins. I think I can build quite a number of various filters to get the rest out before it hits the rafts. I have had good success in a smaller system with a wall of those cheap plastic dish... scrubbies? Aeration/degassing with some Kaldness media to get some biofiltration also. Ultimately, I have a few ideas but it is a very big grey area right now and will be tuned.

I think that should leave me with some pretty cleared out water, I hope.

[Vlad Jovanovic]

Non-engineering related...I would suggest (judging from the clothes that you(?) have on, as well as the look of those bare trees in the photo), that you might want to scrap the talapia in favor of a fish species that would be a bit more appropriate for the environmental conditions of your area.

Are those 16 media beds in your drawing? (Meaning...are you dealing with 16 separate siphons)?...Brave :)

I'm a big wuss, so I opted for a timed flood and drain to my 8 IBC media beds using an indexing valve and a repeat cycle timer. (The 4 DWC's are arranged in a 'conventional' layout...and drain into a large sump). 

So your final DWC is actually your "sump"? (By definition). 

Interesting design.

[Jonathan Hall]

Hey Vlad. No those are not my clothes, just a friend sourced to help me take it down. It was actually a pretty warm day. We were working in brambles and trees a few years old.. Poor greenhouse was glad we saved it.

Yes those are 16 IBC media beds in the drawing. I have considered building a mega siphon so there are not so many going on. However, I have never had too many troubles with them in the past. Nothing that water flow and a big enough drain pipe never solved. It will be 1" pipe in the siphon dropping down to a 3" pvc on an angle taking it to the far corner of the area. From there it will drop down into the chain of various filters underneath them. Which will likely be plumped all together with 4" since I will have pretty high water flow and want to balance the pressure very quickly with the rest of the system.

The final DWC is basically the sump as you have noticed. Water will be pumped to either the fish tanks, or a header tank. Header tank would also act as perhaps a fingerling area. Trying to have everything with a purpose.

Things are likely to change, perhaps with the central bed. The tanks may be pushed to a more central location by a few feet to make room for a burning chamber for a rocket stove. Sort of winging that one. Nothing is set it stone. All depends on the space it ends up consuming.

[TCLynx]

One could use automated diversion valves on the outflow to alternating grow beds and if the fish tanks are high enough, one might even be able to manage to run indexing valves off the outflow from the diversion valves but that would be putting the fish tanks up in the air quite high to feed grow beds at hip high and would make tending the fish tanks tricky.  See even the gravity modified indexing valves require a bit of head pressure and good flow to function.  However the other option requires additional pumps.

If there is twice as much gravel bed as fish tank, then I personally don't see the need for additional solids filtration, especially if the flow to the gravel beds is intermittent (as with timed flood and drain with indexing valves.)  Back in the beginning with constant flow to the grow beds I did notice a bit more sliming issues at the single inlet point to my grow beds, ya know the fish poo pavement that one needs to poke with a stick too often.  Anyway, that doesn't seem to have been a problem since I added the indexing valves.

Anyway, sounds like you have some inkling of what you are getting into.

[Jonathan Hall]

I have looked in to indexing valves a little bit but they made me a little nervous. How long have you been using yours? Have you ever had any fail on you for any reason? Require much maintenance (back pressure spraying)?

In concept they seem like the perfect alternative for me. Mechanical operations just scare me and I like the simplicity of an auto siphon and one pump only. It is my understanding that the plants actually benefit more from the additional breathing time that an indexing valve may provide. In addition the worms would probably do much better as well. Pros and cons...

I am banking on some bit of "slime" to work with. I want to use it on some fruit trees and various other garden plants.

If the beds really do slime up too much, and indexing valves are not used, I will probably throw in a particulate filter of sorts that leads to the swirl filter but I am really hoping this is not going to be that serious of an issue. I may be naive about that though.

In the end, I guess we will all know  if one swirl filter and then heading to 12-13" of media will cause a muck up issue. In fact, I know it will because in at least one tank I am going to test the limits of its stocking density. Luckily they are semi-independent of each other with this design so I can shut off a tank and groups of four at a time.

Anyone have any experience with an 100 micron auto sieve? I have a few ideas in mind of how to build one and have considered exchanging a swirl filter for one to see if it works.

TCLynx said:

One could use automated diversion valves on the outflow to alternating grow beds and if the fish tanks are high enough, one might even be able to manage to run indexing valves off the outflow from the diversion valves but that would be putting the fish tanks up in the air quite high to feed grow beds at hip high and would make tending the fish tanks tricky.  See even the gravity modified indexing valves require a bit of head pressure and good flow to function.  However the other option requires additional pumps.

If there is twice as much gravel bed as fish tank, then I personally don't see the need for additional solids filtration, especially if the flow to the gravel beds is intermittent (as with timed flood and drain with indexing valves.)  Back in the beginning with constant flow to the grow beds I did notice a bit more sliming issues at the single inlet point to my grow beds, ya know the fish poo pavement that one needs to poke with a stick too often.  Anyway, that doesn't seem to have been a problem since I added the indexing valves.

Anyway, sounds like you have some inkling of what you are getting into.

[TCLynx]

Ryan might be able to help with info on the filtration options.

The indexing valves, Failure of an indexing valve usually means that something gets stuck in it causing it to just keep flowing to the same outlet over and over or there is not enough flow and the water trickles out all the outlets but probably not evenly.

Not a big deal usually, just open it and clean out the debris.  Or clean out the pump grate or grate on the pipe feeding the indexing valve.  As long as the valve and flow/pressure are properly balanced or set up in the first place, the debris problem is the only real problem I've had with them.  And when I talk about debris, fish poop doesn't count, I've never had an indexing valve clog with fish poo, the valves actually seem to run better with a nice interior coating of bio-slime too, seems to act as a lubricant.  Debris that has given me a problem are usually twigs, large seeds and leaves from trees around my outdoor systems and once, a snail shell.

I've been running the indexing valves for a few years now I guess.  Worst problem I've had is that the pumps sometimes don't much like the constant turning on/off and I've had to replace impellers.  I'm now switching over to the automated diversion valves in hopes that the pumps will last longer (and I've suddenly found I can expand the system quite a lot.)

But I understand people who prefer to stay simple and avoid extra electronics/timers and so on.  It doesn't necessarily make things more fool proof, it just means there are different things to fool around with.

As to more dry time, actually the timed flood and drain with the sequencing valve means more dry time in my grow beds since each bed is only filling for 5-10 minutes out of each hour and the rest of the hour it gets to drain while in a siphon bed, the bottom of it never drains because as soon as the siphon stops draining the bed is still filling and most siphons I've ever met are flooding/draining several times an hour.  But not that it really matters all that much seeing as the BYAP trials show that to a large extent, as long as there is enough flow and aeration and the top of the media stays dry, even constant flood/flow works just fine for most plants.

I would recommend that you play with spacing a bit first and then if you are putting in the rocket mass heater or anything like that, you need to install that stuff before you start installing the aquaponics since it doesn't work well to be digging and installing that sort of under floor stuff after you have filled up the greenhouse.  Heating coils under the liner of the raft beds is also a grand way to manage the boiler/heat exchange without worrying about running system water through metal pipes.  At least that is how Philip Wolf did some of the heating for the system at We Grow Dreams Over Near Chicago.