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Kidney Week

Abstract: FR-PO472

Reuse of Dialysis Reverse Osmosis System Reject Water for Aquaponics and Hydroponics

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Chang, Eason, Hospital Sultan Abdul Halim, Sungai Petani, Kedah, Malaysia
  • Low, Chun leong, Hospital Sultan Abdul Halim, Sungai Petani, Kedah, Malaysia

Hospital Sultan Abdul Halim hemodialysis unit located in the district of Sungai Petani in Kedah, Malaysia has started operation since 1998. The dialysis unit has 19 hemodialysis machines and is located in 2 separate buildings which caters to about 90 patients.
Hemodialysis is provided by single-pass, proportioning dialysis systems paired with reverse osmosis (RO) system water filtration that rejects 60–70% of the presented mains at the RO system membrane. This reject water is discarded to drain almost universally.


In our unit, the reject water is used for aquaponics and hydroculture since July 2018. The reject water from one of the building has been repiped and the reject water is then pumped into fish tanks.The amount of reject water is estimated to be between 10000 – 12000 litres per day. The state fisheries department collaborated with us by supplying fish tanks, fingerlings and feed for the fishes. Four 1800 litres capacity tanks, three 700 litres capacity tanks and one 1000 litres capacity tank were used.


The fisheries department performed water testing to determine the suitability of the water for aquaculture. The test revealed water temperature of 31 degrees celcius (25-35), pH of 7.76 (6.5-8.5), ammonia level of 0.001 (<0.02 ppm/mg/l) and dissolved oxygen level of 5.84 (>4ppm).
The species of fishes that were bred include Oreochromis aures x Oreochromis mossambicus (Red Tilapia), Oreochromis niloticus (Genetically Improvised Farmed Tilapia), Scortum barcoo (Jade Perch) and Oxyeleotris marmorata (Marble Goby). The fries released were initially 2-3 inches long and weighed about 20-30 grams in average. After a period of 5 months, the fishes grew to an average of 10-11.5 inches and weighed about 400-470 grams.
The nutrient rich water from the fish tanks are then recirculated to the vegetable pots via deep water culture. The vegetables that were grown included Amaranthus dubius (red spinach), Sissoo (brazillian spinach), Brassica juncea (mustard), Mentha (mint) and Allium schoenoprasum (chives). These vegetables were harvested and given to patients for consumption.


Reject water that is actually clean and uncontaminated water can be reused to promote water conservation and used for aquaculture and hydroponic activities with encouraging results. It also provides a good biosecurity enviroment for the fishes to grow.