Lot's of light. I positioned four Nikon SB-900 flash units on the top of the tanks in this series of photos...with the exception of those noted.
As you can see from the photo below all four flash units are lined up on top, diffused and pointing straight down. If you look closely you can see how the flash (second from right) has a much larger base (diffuser). You can see how it more evenly distributes the light at the bottom of the tank. The other three are fixed with Gary Fong light spheres...a more conical beam of light. As with all of my photos I try and set up a "sweet spot" where I plan (hope actually) that the action will happen. The lights to the left and right of the larger unit basically help add a little more dramatic shadows...and a big part of that is just luck and second guessing what the fish will be doing and where.
Keep in mind that each of these flash units have the ability to light a subject twenty feet away. The SB-900 comes with a very cool zoom feature. For these shots I dialed in different settings for each of the units. One of the biggest problems I faced with this and most of my set up is being able to REDUCE the amount of light in the right amounts. SO throughout the shoot, I was changing settings on each. Where I can I will comment on those settings.
My favorite subject....the managuense. On this shot I actually cut all of the spherical diffusers by 85% and bumped up the larger. The nice even light really lights the blues in the fish. I wish it had a little more underneath....but...
You can actually make out where the two diffusers overlapped...lighting the head and back end of the body.
Every once in a while you get lucky with timing. On this shot I actually added a FIFTH flash from the camera head. Full disclosure the image had too much light coming into the front. I cropped very tight on the finished product to get this desired effect.
With all of my photography I try...whenever possible...to capture a bit of the cichlid spirit. Sometimes they cooperate...especially when they are breeding. Here's the female playing to the male near the breeding area.
The shot above where cropped to the two mouths gave me an idea. The male P. coatzacoalcos is always hiding in this ceramic log...looking out at me. I used the "fifth flash" on the camera. Most often the light (if any) coming from the camera is set to manual and goes out at about 1/128th power. In this shot it was set on full TTL power...all of the overhead flash units at about 25% power. The results were pretty dramatic. Without that front flash, all of those beautiful cyans and blues would be in shadow.
This is what happens when the best laid plans go awry. This shot of A. hogaboomorum was taken at the far left side of the lighting set up. The breeding female wandered into the space of the NON breeding male. Every time this happens that male will kick into "impress the bee-yatch" mode. The dramatic shadows add to the picture IMHO.
The other male doesn't take too well to the display and will rush in to retrieve his mate...making for some very nice action photos.
This set up worked great when I put it on one of the 300 gallon tanks. because of the depth, the added power/light worked great. Here's the Platinum Honduran Red Point...beauty in motion.
The female Paratheraps breidohri just outside the breeding area. The fish is about 7".
The male giving her a little attention...since she was nice enough to ask.
Last one...actually shot with the previous over and under lighting set up. Parachromis fredrichsthali. What I like about he photo is that you can see the beautiful fins and the lighting is such that it separates the fish nicely...giving that very soft even light from below.