Laserfiche WebLink
12 JOURNAL OF APPLIED AQUACULTURE <br />N _ (0.097T - 0.215) (9) <br />Nr _ (0.097Tr - 0.215) <br />where T =water temperature and Tr =water temperature at which <br />R was determined. An alternative equation for temperatures from 5 <br />to 25°C was provided by Haug and McCarty (1972). If the equation <br />of Haug and McCarty (1972) is used, Equation 9 can be rewritten <br />as: <br />N _ (O.IIT - 0.20) (10) <br />Nr (O.11Tr - 0.20) <br />Wheaton (1977) suggests that it may be better to use the equation of <br />Haug and McCarty (1972) when culturing fish other than salmo- <br />nids. <br />The ammonia production rate of the fish will also change with <br />temperature. This change must be accommodated by adjusting the <br />ammonia production term (A) based on the relationship between <br />excretory rate and temperature as described by Speece (1973). <br />Water reuse systems are sometimes used to extend the carrying <br />capacity of a water supply that is limited in quantity (Liao and <br />Mayo 1972). Since such applications are not 100% recycle, Equa- <br />tion 1 must be modified to account for the removal of ammonia in <br />water flushed from the system: <br />BA = FZ + LC (11) <br />where L =flush rate (liters/minute). This equation states that, at <br />equilibrium, total ammonia production by the fish (BA) equals the <br />sum of the ammonia removed by the biofilter (FZ) and the ammonia <br />removed by the flush (LC). <br />Adding the preceding adjustments for temperature change and <br />freshwater flush to Equation 8 yields: <br />F (C - C (1 - R ~ o. i iT - 0.20 ~)((XUS1F)/(XtDrSr/Fr))) + LC <br />B - O.IITr - 0.20 (12) <br />A <br />