Westfield Primary Aquaponics Setup

Burnsy

As many of you have probably gleaned from my other posts I am a Primary School Teacher and we are currently in the process of constructing a 5000 litre system using Joel's tanks. It is taking a while as there is a lot to consider with setting it up at a school that you would otherwise not worry about. The construction is part of the learning process and the children are fully involved in it. Part of this is their developing and maintaining the school web site that describes the project.

http://members.iinet.net.au/~westps/kg/kg.html

Above is a link to the school website so those interested can watch it all evolve. Please bear in mind that the website is being developed by 12 year olds so take this into consideration if you have any comments (I will see what I can do about getting the image quailty improved). No much aquaponics yet but it is getting closer by the day so big changes should not be to far away.

Cheers,
Mike

embi

Thats fantastic, that the kids are getting into it...

Grey Mare

Good on you Mike. Keep up the good work!

Burnsy

Starting to take shape, 1 more hour and I will be ready for concrete ..... 28 days till trout arrive :shock:

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embi

Rick

You can't call that a cluttered backyard system. Are you going to be able to keep the scum bags away from it over weekends and holidays? It would be almost a certainty that it would be interfered with in this nice country town.

Anyway, it looks like you will have a terrific setup if the progress so far is anything to go on.

Burnsy

The entire school is fenced and the kids are very excited about it so we are hoping that the ownership of it (they bolted all the stirrups onto the bearers today and lifted it all into place) will stop vandalisim. Most of the vandalisim we get is from the kids themselves, and the tank is going to have a flash lid on it

I do however have some concerns and plan on setting up a motion activated web cam of some sort in the window of the class next to it. As soon as they realise it is monitored when the first vandal gets prosecuted they will stay well enough away.

If anyone has any recommendations for a suitable portable security type camera that is motion activated and comes in under $150 I would be interested.

Web4Deb

I believe the logitech cameras have motion sensor software that comes with it, but it's been a long time since I've purchased one.

However, I'ved used a program called Gotcha (http://www.gotchanow.com) with my camera. I had a couple of punks keep smashing my mailbox. I caught them and sent the video to their parents. :wink:

They came out, dug a new post hole and replace my mailbox. :cheers:

TCLynx

Looking good!!!!! I love hearing about students learning where food comes from.

I have a small concern looking at that picture. That sump tank doesn't have much clearance above the ground. If you ever get heavy rains, what is to protect from water flowing from the ground into the sump tank? Just something to look at before the project gets too far along. For all I know, you never get rain there. I have to make sure I have 4-6 inches above ground to keep the torrential downpours from flowing into my systems overground.

Burnsy

TCLynx wrote:

I have a small concern looking at that picture. That sump tank doesn't have much clearance above the ground. If you ever get heavy rains, what is to protect from water flowing from the ground into the sump tank? Just something to look at before the project gets too far along. For all I know, you never get rain there. I have to make sure I have 4-6 inches above ground to keep the torrential downpours from flowing into my systems overground.

The sump is at least 50mm out of the ground so there is a fair bit of catchment before it overflows but luckily the ground is gutless sand that will soak up water quick smart. Once the decking bearers are raised up off the sand to the final height and concreted in I plan on digging (let me rephrase that - having the kids dig) a trench along the length of the deck to help to deal with any major rain events. We are limited by the surrounds and the levels are everywhere unfortunately. Longer term I would like to see the whole lot covered but that will have to come later after some significant fundraising.

On another note we have decided to do away with the pump in the FT and go CHIFT PIST with a 40mm venturi overflow split off to 25mm down each side of the deck that will feed three of Joel's growbeds each side. What is the best way to calculate the level in the tank that I should set the overflow at?

Burnsy

25 days and counting, joists in so no central trench now. Level tank tomorrow and ensure lid beam and posts are all in the right place then concrete Tuesday

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earthbound

I don;t think your sump is going to be anywhere near big enough to run it chift pist Burnsy. You need enough water to overflow the fish tank and fill the growbeds up. Probably 150-180L per bed plus a bit extra for raising the fish tank level, that could be up to 1000L or more you need to pump out of your sump.. But it's only 500L..

Burnsy

OK there in lies a problem, the reason we were going CHIFT PIST is that the height of the tank as to the grow bed levels is such that we can not run a pump via a timer as the primed pipe would continue to siphon once the pump switched off. Changing to a venturi drain via CHIFT PIST means we eliminated this problem, drop the need for one pump and end up with our second pump being used as a backup. Also from a maintenance point of view we felt that CHIFT via venturi overflow eliminated the possibility that the FT could ever be emptied or run right down through overnight vandalisim if it occurs.

The principle behind CHIFT PIST seems basic enough to me but I have been battling with the concept of what happens if the tank become overfilled, I hypothesise that this should not be a problem as the tank can only drain as fast as the grow bed feed pipes allow and they can be altered via tap so it does not matter if the water level in the tank is higher than the overflow.

I was wondering about the sump volume but was hoping that by choking back infow to the beds, draining the beds via 25mm bell siphons (restricted to 20mm via the reducer in the 40mm waste drain trick) the Ebara running through 40mm pipe would be able to keep up. I also plan to stage the filling of each bed so that it should only rarely if ever dump at the same time to the sump.

What are peoples thoughts? Bear in mind that the design of the deck does allow that the sump could be removed at a latter date and replaced with a higher volume one if needed? It might be that I am trying to rewrite the known laws of CHIFT PIST but I have thought carefully about this and time is not on my side so maybe this is the first school science that the system is going to participate in

I am keen to hear opinions and ideas in regard to this so please post away.

earthbound

It's still not gunna work I don;t reckon..

You will end up with the sump run dry, and the pump will turn off with only a bit of water in the growbeds, not enough to kick in the siphons..

This is the one draw back of chift pist, you need to have a big sump tank...
It's all very well to think that the siphons will be staged, but Murphy steps in and throws a spanner in the works.

Burnsy

No problem if the sump runs right down, we don't need to have any fish or crustaceons in it - my figuring was that it should otherwise the ebara would be running continuously.

What would be the problem with making up the additional volume required in the FT by locating the venturi at the level I suggested and having the tank filled to above the overflow point as I have suggested?

Thanks,
Mike

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