The aquaponics systems culture different organisms that are dependent on nutrients generated fromrnfeed. Most of the time the major protein source of this system is fish meal. However, thernavailability of fish meal is very scarce and the cost is not affordable for developing countries. So,rnthis study was carried out to examine Niger seed cake as replacement of fish meal and also torncompare the anion dynamics of Niger seed cake with fish meal. The experiment was conducted inrnfive treatments, each treatment in duplicate, with the proportion of Niger seed cake; 0% (Control),rn12.5% (TA), 25% (TB), 37.5% (TC), 42.5% (TD). Also a hydroponic treatment (H) was includedrnto examine performance of each treatment on anion dynamics. Samples of fish, lettuce and waterrnwere collected every week for about five weeks. Both phosphorus and nitrogen groups (ammonia,rnnitrite and nitrate) were analyzed by spectrophotometer. The result of the experiment had shownrnthat as the Niger seed cake inclusion increased in the fish feed (43%), TD, the increment of anionrnin the system was observed, which was comparable with the control diet. However, it had lowrnanion loading than the hydroponic solution. In the lettuce, as percentage of the alternative feedrnincreased, the concentration of anion became higher and comparable with the control fish feed. Inrngeneral, the result of the experiment had shown little difference with the fish meal. Therefore,rnhigher percentage of alternative feed from plant sources such as Niger seed cake could be taken asrnsupplementary source of feed.