“…By using filtration technology as mentioned in Section 2.1.2.2, the authors had successfully suppressed the dissolved oxygen to a sufficiently low value, so that subsequent oxygenation experiments can be conducted effectively. The oxygen content in the water has reduced by two folds to 2.64 ppm from the starting 8.18 ppm in the tap water because the carbon compounds in Filter 1, 2, and 4 can absorb oxygen (Delavar & Nabian, 2015;Purnamasari et al, 2019). When the water with 2.64 ppm oxygen content was treated with the magnetic device, its oxygen content increased drastically to 3.97 ppm.…”