Backyard Aquaponics
A place to discuss aquaponics

Hi,

Long time lurker here. I've been devouring the wealth of information in these forums and have decided to take the plunge with a small system. I would greatly appreciate any comments/criticism/corrections/point out major or minor stuffups... it's all welcome.

I have access to a steady supply of 250lt food grade poly barrels so naturally the system is designed around them. I'm trying to heed by the advice often offered here to 'keep it simple' so it's basically a flood/drain system with one pump, and no other moving parts.

Here's the design I've come up with...



So basically the pump in the fish tank pumps up to a 1/2 barrel header tank, which overflows into a 2nd 1/2-barrel, which overflows into the main header tank barrel. It has an autosyphon which will cause it to flood the beds. The beds are linked together with an autosyphon which drains them back into the fish tank.

The overflow on the big header tank and on the beds are there just in case the autosyphons block or otherwise fail.

The pump would run continuously during daylight hours. There's a valve and spraybar tee'd off near the pump outlet which would allow adjustment of the time between floods by diverting away some of the pump's output and therefore taking longer to fill the main header tank.

That's basically it for the hardware.... am I on the right track?

In the top two 1/2-barrel tanks I'd like to try lettuce on styrofoam rafts, silver perch in the fish tank, and a bunch of yabbies in all of the tanks (except the grow beds, of course).

In the grow beds I'll probably start with the easy veggies I'm already experienced with such as tomatoes, zucchini, beans, etc.

Well, that's the plan. I have the barrels and some of the plumbing & hardware. I'm still unsure as to what capacity pump I should be looking at (would 500lt/hr at a 2 meter head for up to 3 floods per hour be sufficient? too little? too much?) Would perlite growing medium (cheap, readily available) work OK?

Cheers,
Gab.

A few points. You probably don't need header tanks and if you are wanting to grow lettuce and such via DWC on rafts, you probably want to place the tanks for that after the grow beds so you don't need to worry about fish poo getting all over the plant roots and causing problems.

You might also read Outbackozzie's system thread for an alternative way to cut the barrels as cutting them the long ways means you need extra support to keep them from bowing out while cutting them around the middle means you can support them with any flat surface of the right height.

Basically, yes your diagram could work but I think you may be making it more complex than it needs to be.
You might look up CHIFT PIST for ways to arrange a system that could work for your rafts and avoid fluctuating the water in the fish tanks so much. (Actually, if the fish were up in the constant height header tanks and you call the fish tank the sump tank, that would be closer to CHIFT PIST. And you then would not really need the big header tank with the siphon, that could turn into a deep grow bed or something else all together.)
If you have access to another type of container for fish tanks, I personally hate barrels as fish tanks as for some reason I have difficulty seeing into them but they can work.

Tip, combined drains and overflows, the pipe that all the drains or overflows feeds into should be large. Always up-size plumbing unless you are trying to balance a siphon.

Big Tip, Add an air pump. Especially if you are only planning on water pumping during the day. You will need the air pump to keep fish healthy overnight and during cycling, you will probably want to have the cycles happen at night as well as during the day.

Oh, I didn't know it could cause problems for the roots... thanks!


Ok, read it, I see what you mean. What if I build a support frame around the beds to prevent the bowing, in order to optimize the grow bed surface area?


I would have preferred a larger fish tank but at this stage it would mean a substantial budget increase and hard to justify it in the family budget, so I have to make do with what I have.

I took your advice and came up with this CHIFT PIST design at lunch time today. I think it addresses all the issues you've mentioned, and you're right it is a simpler system!

It's not in the sketch, but I was thinking that I could add a shallow tub or two over the fish tank to accommodate a raft system. They would have their own pump supplying them from the fish tank and just overflow back into the tank. The pump would be set in the fish tank at the top of the water column to prevent picking up detritus off the bottom.... but it's just an idea for the future at this stage.



Thanks for the plumbing tip, I hadn't quite got to that level of detail yet. I'll definitely be running a couple of aerators, I just omitted them from the sketch for clarity. I've also omitted the 'just in case' overflows from the GB's into the sump - in case the siphon fails.

Even when the GB's are at full flood there should still be enough water in the sump to accommodate yabbies. (?)

Thanks for your advice, here's my updated CHIFT PIST design, how's it look?...



Cheers,
Gab.

Much simpler Gab!!

Could i suggest that you have three auto siphons from the GB's back to the sump. Make take a bit of the pressure off getting the correct return pipe diameter.

Also, the tapered profile that comes with cutting drums lengthwise means that the outside of the bed is potentially a little too shallow for there to be enough rooting depth for the plants. Might be better having the drums cut cross ways so that they're 400 - 450mm deep.

Chatty

+1 on the three autosiphons idea. Check Rupe's system. Lengthwise cut drums will do just fine if you are planting the toms etc in the middle and the leafies towards the edges.

Neat design, Gab!

Ok then, individual siphons on the beds makes sense in that you eliminate a single point of failure, and you could adjust the flow rate and flood depth individually on the beds. So would the beds not be connected to each other? i.e. one may be already flushing while another still in the process of flooding?

Assuming the beds are not connected, how closely matched should the output from the fish tank to each bed be? should I use ball valves on the individual outlets to regulate what portion of the outflow from the fish tank goes into each bed? ...or will the old 'looks about right' be ok?

Nope, don't interconnect them... plumb, flood and drain each seperately.... and use a ball valve on each so that you can regulate the inflow to get the flood depth and siphon initiation right...

Yes you will have to build a frame to support the lengthwise cut grow beds to support them so they don't bow.

+1 on using individual siphons on the beds. (added bonus here is that the sump will usually have a bit more water in it so better for yabbies)

Make sure the pipe from the fish tanks to the grow beds is a few sizes larger than the pump piping. Water under pressure will flow faster than the water being gravity feed out to the grow beds.

Yes you probably will need ball valves on the inlets to the beds to balance the flow to get the siphons to start properly (this can be a little extra tricky with barrels cut the long way since the volume varies with the depth. I know it can be done but at times I have given up on siphons for barrels cut that way.)

You will probably also need a bypass with a valve from the pump feed back into the sump tank in case you pump is more powerful than you need.

As for the raft tanks. Since your sump is going to have relatively clean water that has already gone through grow beds, you can simply take a feed of that main pump to bring water to your raft tanks. No need for an extra pump in the fish tank and you won't have to worry about keeping it from sucking up floating fish food or fish poo from the bottom. Essentially you can have the water from the pump in the sump feed the raft tanks and they can drain to the fish tank or back to the sump tank, whatever works for your space. (This is the beauty of CHIFT PIST with the water in the sump being clean from going through the grow beds, you can then just split off the pump flow to DWC or NFT pipes and it is fairly clean.)

Thanks for taking the time to share the knowledge.

Taking clean water from the sump to feed the raft tanks is so obvious (once you mentioned it) makes me wonder why I didn't think of that.

By the way, TCLynx, if my original design looks familiar to you that's because your barrel-ponics system on your website was the inspiration for my system. Do you still have it running?

Pump capacity. You should move at least the volume of your fish tank each hour. If running the pump constantly then it is pretty easy to work out.

Perlite as a growing medium, I would advise not. It tends to float and clog up everything, even the really big chunky stuff busts up into tiny pieces really easy and will clog the mesh keeping the media back from your drains/siphons. Perlite is also very good at wicking moisture to the surface and holds lots of moisture between flooding so will likely stay too wet and have algae growing on it. It is also kinda dangerous to handle dry perlite as the dust is bad for the lungs.

If going cheap and light is really important to you, scoria or lava rock would be a good choice but it needs really good washing.

If just cheap is important, river rock or river pebbles (non-limestone pea gravel) are a good choice. They are heavy but around here it costs about $52 a ton and is relatively easy to wash.

All media should be washed before putting it into a new system, especially a small system.

Yes I still have the barrel ponics set up. It is now part of my Duckweed Pee Ponics set up.
http://backyardaquaponics.com/forum/viewtopic.php?f=18&t=5199
Currently home to 100s of baby tilapia and frogs in the duckweed tank (no pee dosing since last May.)

I have pretty much always had media in that top tank that the Barrelponics manual uses as a raft bed. That is the only bed I've managed to keep a bell siphon working in long term. I seriously don't advise using that top tank as a raft bed when I note the amount of solids build up I get up in that media even when I have almost no fish in that system and the top bed is full of worms. I have run NFT tubes directly off fish tank water before and the goop that built up around the roots on the plants was amazing and it is no wonder the plants didn't thrive that way.

Anyway, I realized that your original set up was basically a barrel ponics take off. I think you will be happier setting up as a CHIFT PIST arrangement though. Fish tanks seem to stay so much cleaner that way.

With your two barrels connected together as fish tanks. I think I would advise giving each of them a SLO drain even if they are connected together. This will give some redundancy on the overflow and you could perhaps put a valve on the connection between the two tanks so if you needed to shut one off and isolate it for some reason, Repairs etc, you could.

Also, all pipe openings in the fish tank should have grills/screens/grates or something to keep small fish out, you might be surprised at what a fish will try to swim through and finding fish sunning themselves on the gravel just sucks.

Please dont use perlite.

Check this system for barrels cut length wise.
viewtopic.php?f=18&t=6265&st=0&sk=t&sd=a&start=15
+1 on OBO.

That's only a "baby" system... check out Joel's....

http://www.backyardaquaponics.com/forum ... =160&start

Now that's a system!! See Gab, autosiphons on all of them!!

But seeing that Gab wanted to link up two barrels together for the FT Fat Elvis's system looked closer to his idea.