A male JD and male nicaraguense will fight in that small 4 foot length. Adding a female nicraguense would also spell trouble because any of the males in your tank will pair with it, and then cause lots of problems for the other 2 fish.
Do not rely solely on turnover rate for proper filtration. The ammount of bio-media will determine if you have proper filtration. Ammonia and nitrites must be at 0ppm at all times. Use a liquid test to measure each parameter.
Do not rely solely on turnover rate for proper filtration. The ammount of bio-media will determine if you have proper filtration. Ammonia and nitrites must be at 0ppm at all times. Use a liquid test to measure each parameter.