thats what i was thinking,draw a line using the white chalk around the tank,maybe around 30cm distance from the tank to stop the antsIs there no way to keep the ant population out by laying the poison around doors and windows - just in case anything should find it's way into the tank water
Use the magic insecticide chalk Mekaeel is talking about.
The traps might be a problem, as they like too chew things. I am busy cutting pvc pipe and they come in the garage a steel the bits.