Hi Kait,
When fish is so big as yours, you should be able to get a good look at the tube just by gradually raising water temperature to about 86F, and yes it's better to feed lots of food also esp. high protein, ie live food etc...my pair just laid eggs Sept 2, 2000. It's the same pair that you saw pictures of. As usual the tank was NOT in good water condition when they decided to spawn! well i'll just wait and see if fry survives...I did see some tails sticking out on some of them already. Funny thing another pair in other tank just spawned today also!....anyway one of these days....man not enough time, i have Video Tape of my oscars in the process of LAying Eggs etc...and yea try to take some hi-res pictures at many diff angles, short video clips ok too, like 10seconds but like Half-NTSC minimum res.
Joe
www.cichlidfish.com