Aquaculture is among the oldest occupations of human being. Over the past quarter of century, the aquaculture industry has grown rapidly. The effect of water containing sodium sulfate on long term compressive strength of concrete of fishing ponds and channels is investigated in this paper. Aim of this paper was to analyze the strength of concrete channels and of aquaculture which are in direct contact with dissolved sodium sulfate. This is an ongoing laboratory investigation which consisted of 480 standard casting concrete cube mix designs and subjecting them to different curing condition environments. Analyzing laboratory results, it was found that for short period of time, the effect was negligible, but for longer periods up to seven months, EC (electrical conductivity) of water had a low negative effect on compressive strength of concrete, while specimens were placed in waters with different ECs. On the other hand, average compressive strength of concrete was almost 25 kg/cm2 lower than estimated. However, loading the sample concretes up to failure resulted in strength loss of up to 10%. To solve this problem, designed compressive strength must be considered 10% higher than actual in order to have an acceptable concrete strength for water channels and ponds which are in direct contact with sodium sulfate ions in the water.