@article { author = {Babapour, Mohammad and Rafiee, Gholamreza}, title = {The Influence of Serial Ozonation on Water Quality and Growth Performance of Rainbow Trout (Oncorhynchus mykiss) in a Recirculating Culture System}, journal = {Journal of Fisheries}, volume = {71}, number = {4}, pages = {342-351}, year = {2019}, publisher = {}, issn = {2008-5729}, eissn = {2423-7809}, doi = {10.22059/jfisheries.2019.272470.1079}, abstract = {With the development of aquaculture during last years, there is increasing need to intensive culture methods and using recirculating water without losing its quality. Using ozone as a potent oxidant agent would lead to convert TAN and nitrite to nitrate and decrease in water turbidity. Among different methods of ozone injection, the method of serial injection has lower qualitative fluctuation and toxic impacts compared to others. The present study was conducted based on a factorial experimental design with a control (without ozone injection) and three ozonation levels (100-120, 250-300, and 450-500 mV) three times per day, each time 3 hours  after feeding with two levels of water exchange (2 and 6% of total water volume). Twenty fingerling of rainbow trout, O. mykiss, (17.2±2 g) were randomly distributed to experimental tanks. Measurement of the water quality parameters and biometry of fish were determined during study period. Serial injection of ozone was led to increase and decrease of nitrate and nitrite, respectively (P<0.05), both of them were less in 6% than 2% water make up. Although the highest ozone level reduced 17.6% TDS, but this change was not statistically significant (P>0.05), Also, ozone and its interaction with the water make up, did not have a significant effect on total ammonia and total phosphorus (P>0.05). On the other hand, water make up had significant effects on concentration of TDS (P<0.01), total ammonia and total phosphorus (P<0.05). While the effect of water make up and its interaction with ozone levels on nitrate and nitrite concentration was not significant (P>0.05). Ozone significantly affected on (FCR) decreasing, condition factor (CF) and specific growth rate (SGR) increasing (P<0.05); while water make up and its interactions with ozone levels did not have a significant effect on these issues (P>0.05). Based on the results, it can be said that using ozone in ORP level about 450-500 mV, improved water quality and ozonation along with an increase in make-up water level to 6% would lead to decrease in food conversion ratio and improve of condition factor and specific growth rate, and is a useful approach that can be used in super intensive and recirculated aquaculture systems.}, keywords = {Super intensive culture,Water quality,Ozonation,Recirculating water}, title_fa = {تأثیر اُزن زنی سریالی بر کیفیت آب پرورشی و شاخص های رشد بچه ماهی قزل آلای رنگین کمان (Oncorhynchus mykiss) در سیستم برگشتی}, abstract_fa = {با توسعه آبزی­ پروری، نیاز به پرورش متراکم­ تر آبزیان و استفاده از آب برگشتی علیرغم کاهش کیفیت آب پرورشی، افزایش یافته است. ازن به ­عنوان یک اکسید کننده قوی می ­تواند باعث تبدیل آمونیاک و نیتریت به نیترات و کاهش کدورت آب شود. از بین روش­ های مختلف تزریق ازن، روش تزریق سریالی نوسان کیفی و اثرات استرسی کمتری نسبت به روش ­های دیگر دارد. این پژوهش در قالب طرح فاکتوریل و بر اساس سه سطح ازن (mV 120-300،100-500،250-450 و تیمار بدون ازن) سه بار در روز به مدت یک ساعت، سه ساعت بعد از غذادهی و با دو نرخ تعویض آب (2 و 6 درصد حجم کل) در 3 تکرار انجام شد. تعداد 20 قطعه بچه ماهی 2±17/2 گرمی به طور تصادفی در هر واحد آزمایشی توزیع گردید. فاکتورهای کیفیت آب و پارامترهای بیومتری ماهیان سنجش شد. تزریق سریالی ازن به ترتیب موجب افزایش و کاهش معنی­ دار نیترات و نیتریت شد(0/05>P)، هر دو این عوامل در نرخ تعویض 6 درصد کمتر از 2 درصد بودند. با وجود این که بالاترین سطح ازن موجب کاهش 17/6 (0/05P)، آمونیاک کل و فسفر کل تاثیر معنی­ داری داشت (0/05>P)، در حالی ­که تاثیر نرخ تعویض آب و اثر متقابل آن با سطوح ازن بر غلظت نیترات و نیتریت معنی دار نبود (0/05P)، در حالی­ که نرخ تعویض آب و اثر متقابل آن با ازن در این موارد تاثیر معنی­ داری نداشت (0/05