the last time i had to net fish in this type of situation was when 4 blue/green tiger barbs needed removing from my 36ins by 18ins by 15ins planted community tank. (sorry...i know tanks in measurements not volume). they had to be taken out as they were worrying the other fish with their fast, aggresive behaviour. unfortunately, it was this fast behaviour of theirs that made it difficult. i spent hours trying to chase them with the nets...and only caught one. so i came up with an idea by thinking like the tiger barbs. they are a fish that get very hungry as they are so fast moving...and i had been chasing them for hours, so they must have been starving. so i placed some food in the big net, and held it still in the water. when one of the tiger barbs went in to get some (and when the neons finally left the net...) i would jerk it up, and the fish was caught. this worked for 2 more fish, so i had just one more to go....i left it for a day, hoping it will get lonely and come to its senses and agree to get caught. unfortunately, my skills as a diplomat didnt work...and he didnt fall for the food in the net trick (he was a smart one who had learnt his lesson....). so it was back to chasing him with the nets....he was eventually caught acouple of days later, and reeunited with his friends in a 18ins by 12ins by 12ins tank i had set up for some small shelldwelling cichlids...and they are still theer with afew more tiger barb friends - so my dreams of those shelldwellers havent come true yet, much to the pity. but it is a very colourful and lively little tank all the same.