We did not managed to catch any interesting fishes this time round but instead we located a fast flowing stream with C. affinis inside. This is the first time I found cryptocorynes in the wilderness in Malaysia (haha, don't laugh, I have been searching in the wrong places previously). And we were lucky to find a spathe to help in the identification process.
This is a close up of the substrate composition in this stream. Its a pity I forgot to collect some of the stream's water back to test the pH. (Added the substrate to distilled water with pH 6.6 and tested the distilled water after 2 weeks, the pH has rose to 7).