Krishna

Small Scale iAVS for an orphanage

5 posts in this topic

Brief Intro:

I am Phani Krishna, living and working in UK. During my vacation to India, I am setting up a small scale iAVS system at an orphanage in hyderabad, to establish their own food supply system. I have made some progress with the project and now I feel I need some help from the community to take my ideas forward.

The project is being established at the kitchen backyard of the shelter home. The area was all dirty and infested with wild rats earlier and hence I took the decision to pour a concrete slab at the ground level to be sure about the environment for the system. The tank size is approximately 25000 litres with a depth of 2 metres.

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Size of Tank: 1.5 x 3 x 6m (slope of 1ft towards North East)

Proposed fish tank usage volume:  14 cu.m. (can be reduced to suit the growing area)

 

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Size of 1 grow media bed: 1.3m x 3m x 0.42m (area 3.9sq.m.), central drain of about 30mm dia

 

Total Grow Beds : 11 (can be extended on requirement)

Total Growing Volume: 17.16 cu.m

The concrete ground is sloping from south east to north east with a 1foot slope approximately.

Pump Details:

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Inlet Size: 32mm

Outlet Size 25mm

Head : 17 to 27m

Discharge : 180 LPM

 

Since this is my first aquaponics/iAVS project, I am planning to use the tank only partially untill the shelter home staff get accustomed to the system and its use, while I also learn and fine tune the variables.

In the attached pictures of the area, one can see the brick lines of proposed biofilter beds for growing plants. We have set it up as a bed size of 1.3x3m with 0.3 to 0.4m wall/walkway between the beds. To pump water from the tank, we have selected a 1hp openwell submersible pump.

I have not yet got the sand delivered and hence could not do conductivity test and pH test for the system. Meanwhile, I am planning to install the pump and plumbing for the system. I am not sure of the pump selection and plumbing arrangement. I am of the opinion that water supply for all the beds will be piped to the pump, but in this case, the flow will be different in the first bed when compared to the last bed due to the distance the water has to travel from the pump. How to manage to get constant or similar flow rate on all bed supply points ?

Is the pump selection approximately matching the system ? Is it better to increase the biofilter area to match 1:2 ratio of tank to grow media ? I have not yet decided on the quantity and type of fish but to begin with, I am planning to introduce ornamental fish like Gold fish (because the institution follows Gandhian philosophy of vegetarian diet).

The organization for which I am setting up this system is a NGO established by Mahatma Gandhi. They provide shelter for victims of rape, social abuse, trafficking etc. I feel privileged to have the opportunity to contribute to such a cause in my own little way. Any help from this forum to help me complete the project is greatly appreciated !

 

 

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God bless you for doing this. I wish I could help but my forte is not aquaponics but rearing fish. I hope others will chime in. 

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I think your pump should do just fine.  

Put valves on your supply line at the points where each line feeds each bed.  You will need to control how much water flows into each bed.  In doing so, the water pressure will equalize along the entire length and each bed should get plenty of water.  Probably take a little trial and error to get everything set just the way you want.  Plus, the situation in each bed will change along the way as each bed matures, so the valves will help keep things under control.

 

Also, register here https://www.havemoreforless.com/  for additional assistance. 

Edited by Aufin
Additional info (see edit history)

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10 hours ago, Aufin said:

I think your pump should do just fine.  

Put valves on your supply line at the points where each line feeds each bed.  You will need to control how much water flows into each bed.  In doing so, the water pressure will equalize along the entire length and each bed should get plenty of water.  Probably take a little trial and error to get everything set just the way you want.  Plus, the situation in each bed will change along the way as each bed matures, so the valves will help keep things under control.

 

Also, register here https://www.havemoreforless.com/  for additional assistance. 

Thanks for the response. I am going shopping today to procure sand and also if possible the pressure regulator valves. I have never done this before, so your inputs are very useful!

The valves i found as a reference for shopping is http://www.watts.com/pages/_products_details.asp?pid=6815 

I hope this is similar to what you suggested. Since I am planning for 11 beds right now and some expansion to balance the system, i will get 15 such valves according to the motor head ( I have not yet procured the motor, but i will do that along with the valves). My idea of tuning the system is by turning the motor on with full flow into the supply pipe, reduce the pressure using these valves to make sure all the beds flood at the same time or close enough . This means each valve might have a different pressure setting, based on the inlet pressure at that bed/supply side. Please correct me if i am wrong here.

Coming to the sand part, I have contacted a few suppliers today and will be visiting them soon. Some suppliers have a brownish color sand and some have white/cream colored Sand. All of them claim to be quartx silica sand of 30-60 mesh and 80-120 mesh. Is there a difference in quality or efficiency based on the color/type ? I will do the vinegar test to check pH of the sand before buying. Is there anything else I can use as pointers for my shopping ?

 

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Not familiar with the valve you chose.  It looks much more high tech and more expensive than what I had in mind.  This is what I use.....a simple ball valve.

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As to the sand, Gary D. needs to come along and help on that.  

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