Vietnamese Koi (Anabas testudineus) farming in Aquaponics – Trial Update

March 1, 2019

Brief Background

Vietnamese koi is getting popularized in Maharashtra state due to its higher market potential and high growth with attractive FCR. Koi has added advantage in aquaponics farming due to its higher tolerance to lower water DO, higher nitrate level and wide choice of feed (omnivorous feeding). Said trial was conducted during June 2018 to December 2018 at Vigyan ashram Aquaponics farm setup.

System details

Fish tank – HDPE lined fish tank of approximately 15000 lit with bottom drain connected to separate sludge tank.

Bio-bed- Bio-beds where constructed using lose brick structure & HDPE plastic liner with volume of approximately 7000 lit . Bio-beds were connected to each other by flood & drain based siphons system. Water was taken back to fish tank after circulating in bio-beds. Bio-beds filled with red earthen brick as bio-media and planted with Japaneses mint (Mentha spicata) & Alu / Taru (Colocasia esculenta).

Water circulation – Water from fish tank is taken out in separate sludge thank through bottom drain. Water from sludge tank is pumped to bio-beds with submersible sludge pump connected through automated timer. Bio-beds were connected to each other by flood & drain system to take water back to fish tank.

Water quality parameters- Water DO is maintained by fixing air pump (airflow of 35 Lit/Hr) with power backup system. Water DO was maintained around 6 to 7 ppm. Water ammonia (NH4 ) was maintained below 0.5 ppm by circulation through bio-beds. Water temperature was kept between 22 to 28 ° C by restricting evaporative cooling by covering bio-bed & fish tank with UV stabilize polyhouse paper.

Fish feed & feeding interval- Fish fed with 0.8 to 4 mm floating pallets with 28 to 32 % protein @ 10 to 2 % feeding rate during trial perios. Feed was given 4 times/day @ equal interval during day time. Fish were also fed with fresh azolla @ 500 gm/day (not taken into calculation of FCR).


Result –

Fish growth & FCR – Total of 800 fish fingerlings of koi and  40 yearlings (average 60 gm) of grass carp were raised during June to December period. The final fish density was 5 Kg / lit of water. Average fish weight achieved during 7 months raring was 53.75 gm with average length of 18 Cm / per fish. Total of 73 Kg fish were harvested at end of trial with FCR of 2.01 (147 Kg fish floating pellet feed used).


Market rate & Sales – Koi has good market potential. Fresh fish were sold @ 200 Rs/ Kg in Pune city as wholesale price.

Difficulties faced & way forward- Following were some of the difficulties faced during trial –

  • Fish mortality- Very heavy (almost 80 %) fish mortality was faced during trial. Its was mainly higher stress levels due to high stocking density leading to fungal infection. Its been also observed that Koi has very strong cannibalism nature. During course of experiment separate trials were conducted to standardize stocking density of koi fingerlings & treatment methodology so as to avoid these issues in aquaponics farming. Experiment results available on – https://vigyanashram.files.wordpress.com/2019/01/fish-trial-paper-i.pdf
  • Un-even growth of fish- Its found that koi has very high degree of un-even growth rate. It may be due to aggressive nature of healthy fingerlings. Its found that in aquaponics separation (sizing), selective feeding etc may need to adopt for even growth & harvesting.
  • Water losses & pump failures – Failure of water pump, electrical failures and leakages in bio-bed, fish tank were some of the frequent issues during trial. Its affected overall water quality parameters mainly higher ammonia concentrations during later stage of trial affecting overall growth rate & FCR.


Its found that Koi has good potential for aquaponics farming due to adaptability of lower quality water parameters, higher tolerance and market potential but Koi farming is also bit tricky due to its strong cannibalism nature.  Aquaponics farmers can adopt koi with very good returns provided they got enough knowledge & skills in koi handling with market demand study.


Autofarm – A real time Soil moisture, Temperature, Humidity monitor for farmers

February 16, 2019

Auto Farm  :  A controller for precision agriculture. 

Problem being address : 

Its important if we monitor major parameters like Temperature, Soil moisture, Humidity inside poly house for better plant health and growth. Devices available in market to monitor all those are expensive – having modules for each parameter with individual cost and made for large scale farming. For small scale farmers with limited annual income needs such device in low cost to increase crop yield and income.

Features : 

  • Controls Temperature , Humidity and Soil moisture parameters
  • Data will get on Mobile via Bluetooth.
  • Available for single phase and Three phase application.
  • Low cost, easy to operate & maintains.

Technical specifications : 

  • Customised Temperature and Humidity sensor with higher accuracy
  • Operating Voltage : 12VDC -1 amp , External Source : 230+- 10 VAC
  • Weight : 500 gms , Size : 145mm X 190mm
  • Rust free Soil moisture sensor cable length: 5 meter.
  • Data availability on Mobile Distance: 100 meter maximum.
  • Re programmable as per crop.




Build your own hydroponics – Tamil Language link

January 27, 2019

Dear viewers thanks a lot for our overwhelming response to our hydroponics fodder making video. On demand from Tamil viewers  we are happy to upload following document.

hydroponics fodder cultivation unit parts & specifications (in tamil) (1)


Standardization of stocking density & treatment methodology of Vietnamese Koi fish fry.

January 26, 2019


Dear readers its our pleasure to share our experience in treatment of fish fry. A said experiment was carried out as part of aquaponics trials study during July – December 2018. Aim of study was to standardize stocking density & treatment methodology for Vietnamese Koi fish before releasing them in actual aquaponics system.

fish trial paper i

Please let us know your comments on above paper : vapabaldst@gmail.com 


Aquaponics training workshop @ 24-25 November 2018

November 20, 2018

We are pleased to announce a 2 days training workshop on’ Aquaponics farming’ on 24th & 25th November 2018. This training is aimed to share our experience in aquaponics farming during past 4 years. Training will cover aquaponics system design , system biology , water chemistry along with commercial aspects like feed conversion rations , economics , return on investment (ROI) etc. 

We have limited 10 seats for training (Sorry for last minute posting !!) . Request you to circulate post in like-minded groups / pages and contact vapabaldst@gmail.com for any further clarifications / information, 


DIY – Digital hygrometer

October 22, 2018

n Pune market , digital hygrometers are either very costly or low cost versions are having very high error margin. We needed high accuracy hygrometers for our ‘drying apparatus’  , so we build it by studying analog (dry bulb / wet bulb) hygrometer basic working principles coupled with arduino based programming / computing.

DIC student Jaydip has worked on this and here are its details –



Taking Pune’s DIY culture a STEP ahead…

October 20, 2018

Vigyan ashram , Do-It-Yourself lab Pune is happy to announce Diwali vacation’ DIY camp’  during 3-17 November 2018. This camp is targeted for 8+ age group students with spark of Diwali lightning! Camps will explore application of new technologies like robotics , 3D printing , laser cutting etc for making of sky lanterns , electronics fire-crackers , traditional decorative items like idols , show pieces etc in very constructive learning manner. Interested students / parents are requested to register before 25/10/2018 to assure their seat. Please contact 94042251930 / 9067157281 for further details.