You may be surprised at how little I change the water, but as long as the fish are healthy and spawning, something must be right. Water chemistry plays an important role in the well being of your Neolamprologus brevis and is important when trying to spawn them. The water needs to be hard and alkaline. I use baking soda to raise the pH to its level. I use Epsom salt to raise the hardness.
Epsom salt is basically magnesium and that is one element which hardens the water.
Once you have your Neolamprologus brevis , and you are looking for signs of a pair bond, the main thing to look for is that a male and female are sharing a shell. I find that once the lights are turned off, and it's time for bed, the female goes into her shell and the male squeezes what he can of himself into the rest of the shell. If you ever see the female pecking at the males flanks, this is also a sign that they are a pair and are soon going to spawn. Feeding special foods is not very important in conditioning your Neolamprologus brevis . I have found that a steady diet of high protein food and a staple of flakes does good for them.