Establishing fish tank size

[Jerry Nissen]

My target is to produce about 1 pound of tilapia per day...... What size tank will be required?  Thanks

jerry

[Keith Rowan]

BIG...1 pould of fish, or 1 pound of eatable flesh? it takes an average of 4 yellow perch fillets to make 1lb.. with tilapia, it will depend.. with my tilapia, i have a couple that are over 2lbs, will give me less than 1lb of meat each..(30-37% of the fish's total weight will be the yield)

i've got to the point where i can pull a fish dinner from my basement 1x (at least 2 fish) a week for myself and the wife (for 1 year).. and i've got about 1500 gallons between fish/minnows and crayfish..

my main ft is 700 gallons..

 

 

[Harold Sukhbir]

Hi Jerry,

Approximately 3000 gallons of Tank size.

[Rob Nash]

1 pound of tilapia fillets will take 3lbs of whole fish per day..

3lb x 365 days = 1095 lbs/year

at 1/2 lb/gallon max stocking rate.. you will need 2190 gallons.. go with 3,000

...not all the fish will grow at the same rate. ...it takes tilapia 1-1/2 years to grow to 1-1/2lb plate size.

don't believe the hype about tilapia that grow to 1-1/2lb in 9mos... aint gona happen.

for 3,000 gallons of tank water you will need around 750 sft of media beds,, but could "stretch" it out to 3,000 sft!

that's one heck of a back yard garden! 

 

[drumurphy]

Sylvia has a really good recap for planning your tank and grow bed ratios in the "Start Here/Rules of Thumb" section on the home page. She knows her stuff - listen and learn - I did.

I personally have become even more conservative than her #'s when it comes to the tank density and media bed ratio requirements. 

Remember - aquaponics is about 1st - water conservation and 2nd - accelerated "low labor" (hahaha) vegetable production, and 3rd - organic production if that matters to you and you want it, or 3rd-#2 doing it your self etc .... The fish protein component is an added plus way down in far off 4th or 5th or 6th place. People come pretty regularly to see our systems, and when tours come through they always start asking about the aquaculture production side of things, and that's not really the point of aquaponics IMHO. The big problem (among many) smallish commercial AP installations is that to grow enough fish for that side of production to be dependably commercially viable, or say, to have a supply stream that is large enough and consistent and dependable enough to make it worth you or a customer's while, you need to have some pretty sizable produce production.Its about veggies ...

We run hybrid systems with both Media and Raft grow beds. I believe your aquaculture tank/s needs to be at least 7+ gallons per pound of fish - minimum - that would be the whole beast, not the 12 oz filet. And remember you need to size your tank for the end of the growth cycle, not initial headcount.

To accommodate and utilize the waste products from that fish without dumping all that good stuff down the drain every other day cleaning filters (the whole idea behind AP), I advocate at least 1 sq ft of media bed, worms a must, and 2 sq ft of DWRaft, which adds at least another 18 or so gallons of water per fish (a cubic ft of water is 7.5 gallons +/-). It's our 7/2/1 rule.

Lots of people advocate higher fish densities and emphasize how much fish protein you can grow, but IMHO if your want healthy fish and a healthy system (one and the the same thing), you need to de-emphasize maxim fish population and look to the tomatoes for happiness.

In my limited experience it is easy to wake up to too much fish mass in your system and the subsequent instabilities in the ecosystem that overpopulation creates. If your system ever smells the slightest bit un-sweet, it's too much food or too many fish  - for sure too much waste of one kind or the other.  A good metaphor for lots of things ..... I've found almost all of my past problems were caused by trying to push high fish #'s, or shocking the system with radical fish or produce harvesting. You need to plan ahead, and take smallish action. Clearing our half your raft tanks all at once is like clear cutting a forest - with just about the same results. Pulling a tank full of adult fish is the same thing as well.

We also run 2 aquaculture tanks, one large one for adult grow out, and one for fry to juvenile, which smooths out the harvest impact as well as holding closer to consistent size/feed utilization. If you keep your fish uniform size, stable temps and water quality, and manage the feed regime carefully you can grow out a 2+ lb tilapia in 9 months - or less - in the conditions above. If you pack them in tight, their growth slows way way down. Currently I have maybe 80 fry in a 20 gal aquarium from the same brood as the fry in my juvenile tank. The aquarium full of crowded fingerlings are about 1.25 " and have been there for 2 months. The 25 fry (same brood) in the 130 gallon juvenile tank are going on 4", and got there in the same 2 months. You can't hold fry like this for ever, but you can for quite a while. It is a clear demonstration of the impact on growth rates tank density can have. I'll post a couple of photos.

BTW - I tried eating tilapia as my (almost) full time protein source ... it gets really pretty boring (read unappealing) pretty fast ... you start looking at the styro shipping peanuts ....

Best regards

 

  

 

[George]

Lots of good info, dru.  thanks.
drumurphy said:

Sylvia has a really good recap for planning your tank and grow bed ratios in the "Start Here/Rules of Thumb" section on the home page. She knows her stuff - listen and learn - I did.

[Jerry Nissen]

I have a very basic question.......

With my limited mentality, I cannot find the "post" button to post a comment.....  Does anyone else have a problem using this forum?

Sorry to be so dense.