Last month we went over how to keep a pair, this month we will go over breeding tank set up.
The first thing to be aware of is that mature Flowerhorn are very strong and no matter what you do, they will most likely completely rearrange the tank when they spawn. As part of the pre spawning courtship, they will move, pile, re-move and then pile again any gravel in the tank. They like to spawn on flat, horizontal surfaces. I always place several large pieces of slate to lay flat on the bottom of the tank. Flowerhorn can lay up to a thousand eggs at one spawning, so you need to make sure the pieces of slate are at least 8 x 8 inches.
With that said, it is my experience that they usually choose to remove all of the gravel from an area of the bottom of the tank and actually lay the eggs on the glass bottom of the tank.
Directly prior to spawning, the male sometimes will brutally hurt the female. During spawning, they will often get along fine. Directly after spawning, the female will become extremely protective of the eggs and I have seen her actually beat up and kill a male that just days before was abusing her. I mention this so you will know that it is extremely important for you to have plenty of hiding places in the tank during the entire breeding process. I usually try and put several 8 inch pieces of PCV pipe in the tank that are large enough for the female to go into, but small enough that the male, who is usually larger, cannot go into. This can be easily accomplished as PCV piping is sold in 2, 3, 4 and 6 inch diameter sizes. Also, I always place several pieces of driftwood, that are riddled with large holes, in the tank. I usually will stack them on top of each other to great a small hill of porous caves.
I always add extra filtration to the tank a day after the eggs are laid to keep the water exceptionally clean during hatching. I remove the extra filter directly before the babies become free swimming.