Need a practical design for a fish farm.

[Pugo]

I want to build four rectangular fish tanks, each of them I would like to 2,500 gallons each. 12 ft x 8 ft x 4ft. Is what the general idea is right now. I am trying to figure out a good tank design, a very simple filtration system. That will handle 8,000 Tilapia as the grow out weigh will be 250 grams max. I want to run the whole system with one pump. The fish tanks will be made of concrete.

The Fish farm will be in Mindanao, so I will need to use a very simple filtration system as things that are available are limited. Anyone willing to lend a hand would be welcome.

[ande]

I want to build four rectangular fish tanks, each of them I would like to 2,500 gallons each. 12 ft x 8 ft x 4ft. Is what the general idea is right now. I am trying to figure out a good tank design, a very simple filtration system. That will handle 8,000 Tilapia as the grow out weigh will be 250 grams max. I want to run the whole system with one pump. The fish tanks will be made of concrete.

The Fish farm will be in Mindanao, so I will need to use a very simple filtration system as things that are available are limited. Anyone willing to lend a hand would be welcome.

Hi Pugo
That is 2000 x 250grams (500kilo) in each tank off 2500gallon (US or IMP?) right?
cheers

[Pugo]

That would be US gallons.

[Earthan Group]

4 tanks
9000 liter tanks (allow free board)
36000 liters no including filters sumps and pipe work
3600 liters of water exchange per day
1,314,000 liters of water used per year (10% exchange per day)
2000 fish in each
500 kg in each
55kg/1000 liters
222 fish per 1000 liters
2000kg standing biomass
200 days for grow out (guess)
1.25 grams per day average growth (each fish)
10kg per day total
1.5 feed conversion (guess)
2% feed bw/day
40kg feed per day when bio mass is reached.
3600kg yearly production estimate

You can work out your aeration. pumping and bio filtration needs from there. If I have more time later I will complete it.

[Pugo]

Earthan Group
Thanks. I will be staggering the fish harvests, but the grow harvest weight is 200 to 250 grams. As this is the market size of Tilapia in the Philippines so grow out is something like 135 days. Also need to plan for a small hatchery on site. I think four tanks each tanks only being 4'X4'X3' two tanks for breeding and two for fry.. I think the big thing will be working out a biofilter design that is inexpensive to construct.

[Earthan Group]

4 tanks
9000 liter tanks (allow free board)
36000 liters no including filters sumps and pipe work
3600 liters of water exchange per day
1,314,000 liters of water used per year (10% exchange per day)

2000 fish in each
8000 fish total
500 kg in each
55kg/1000 liters
222 fish per 1000 liters
2000kg standing biomass
5400kg yearly production estimate

135 days for grow out
1.85 grams per day average growth (each fish)
15kg growth per day total
1.5 feed conversion (questionable)
1.2% feed bw/day
23kg feed per day when bio mass is reached.
8100kg of feed per year.

8kg of solid waste per day
2920 kg of solid waste per year
36000 liters per hour for solids removal (@ 50% efficient)

2000 liters of k1 for bio filter
3000 liter vessel for bio filter
24000 liters per hour minimum
54000 liters per hour maximum discharge flow (after dynamic and static head loses)

800L/m side channel blower may cope with the feed load.

In general, your pipe outlets will be 100mm or even 150mm but 100 outlet into a 150mm manifold will do the job provided you are not wanting the water to travel too far by gravity (most don't). Your inlets will be something like 50mm or 65mm into the tanks from a 100mm manifold. Remember to put lots of I/O in that lines for cleaning.

Something like that anyway. There is a bit more to designing a farm than that but the key areas are enough aeration, enough water flow, adequate solids removal and a large enough bio filter.

Above all else, have fun!

[kingjam]

Here are some ideas that may help you. I like their plan for making a cheap vortex swirl filter for solid waste removal. It appears to be doing the job well. I myself am planning on making one or my system.
http://www.youtube.com/user/TheUrbanFarmingGuys#p/search/0/39xT5xzNu3s[/URL]

Kingjam

[Pugo]

Earthan Group
Thanks you confirmed my numbers. That was a big help.
kingjam
Thank you, I have seen there design it works well for them. I am thinking to incorporate a swirl filter into the design as there is little to it.

But I am really trying to do this will less, I want to do this with the least amount of technology or high tech products possible. I am talking Mindanao.. So this whole system has to be very basic, The work force will be unskilled and the only person that will understand it will be me and no man is island.. so it really has to be simple basic I need to make this as goof proof as possible using local materials if I can.. So if I can just use one pump to run the system the better off I will be.

I thought I would use the water pump to do the aeration by letting the water fall into the tank as I have seen many others do.. I was thinking if I had no choice I could build a degassing tank and put a small blower there. which would also help aeration of the water. But Power to the system is not as reliable as in the western world. once a week at least there is a loss of power sometimes all day and only comes back as gets dark. Another reason to keep it basic, because I may be forced add a solar system to the fish farm to keep running..

[Earthan Group]

I thought I would use the water pump to do the aeration by letting the water fall into the tank as I have seen many others do..

Two comprimises come to mind, lower density (much lower) and much bigger water pump. If you do that, you may need a much bigger bio filter. It is all relative Pugo.

[Pugo]

I know I feel like I am banging my head on the wall, But as always I don't think there is going to be a short cut for me.. I haven't seen any older technology that I can use at this point. I'm thinking I will have to place the MBR underground next to the sump tank. So the MBR just empties straight to the sump.. I will have to get a blower that will run the MBR and aerate the four tanks.. How much air do you think I will need to move 2000 liters of K1? That and finding a very reliable pump that move 15,000 gallons per hour. I was planning on 4 inch lines, now it looks like 6 inch lines..no problem easy to do at this point.. As this is my retirement project..