I need to do a feasibility analysis of application of semi- closed RAS (75%). I have 40 liters/second inlet water and 30 liters/second re-circulated water, total flow of water in the system is 70 liters/second. I have 11 ponds for trout production with 4,487m3 of total volume of water. Taking into account FAO standards, max 25 kg/m3 should be kept, which means that total production is 112,175 kg.
I am wondering if there is another standard for calculating total production of trout taking into account water flow rate. I would like to mention, that water in this aquaculture facility is re-circulated sequentially (pond by pond). Usually, in semi- closed RAS what is the optimal volume of fish production per liter of water with proper bio-filtration and mechanical filtration and aeration?
This article might be of interest to you. http://www2.ca.uky.edu/wkrec/TroutInventoryManagement.pdf . I would watch the limiting factors of Dissolved Oxygen, Ammonia concentration, Ph very closely. Trout, are of course very sensitive to low DO levels. Culturists often forget to consider the weather i.e. a low pressure weather system can drop the DO levels in the water dramatically simply because there is not enough pressure to keep the oxygen gas dissolved into solution.
Thank you for your advice. Of course, we are paying attention to all crucial water quality parameters.
Sure, so to answer your question more specifically. A heavy stocking of fish would be ~ 1/2 pound / gallon of water. This is somewhat species specific and hugely dependent on water quality. If you want to be conservative you might start out with 1/4 pound /gal. For flowing water calculations consider 10,000 to 15,000 pounds /cu ft /sec of water.
DO is critical because fish growth is dependent on oxygen uptake. DO is temperature dependent (colder water can contain more). The limiting factor for uptake by fish is the gill surface in relation to body weight (surface grows by the power of 2, weight (body mass) by approximately 3). Juveniles grow fast provided temperature and DO content are within their preferred range, but with increasing size the gas exchange surface becomes limiting. Food is a necessary, but insufficient condition to explain growth.
Can any one inform me how to calculate the respiratory surface of fish gil ?
Hi, have a look at this publication and references therein: https://pdfs.semanticscholar.org/5694/fefe9069a497ced827e5aa7c553e2f9db7a3.pdf
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