There are a couple problems with Flowerhorns, as there are with any cichlid or pet of any kind.

Darkening
Darkening is common with Flowerhorns and is an attempt for the flowerhorn to mimic its natural surroundings. All fish do this to some extent. So, a Flowerhorn kept in a tank with a black or dark background will be darker than a fish on a light-gravel background. My fish Bebe is in a tank with a pale brown river gravel. This, plus the absence of a dark background keep her colors at their best.

Keeping Flowerhorns on a black background is not recommended and will result in dark, maroon-colored fish.

Aggressiveness
Flowerhorns are meaner to their rivals than to any other animal or fish. They spar lightly with a tankmate plecostomus and might even completely ignore smaller Flowerhorns, but two Flowerhorns of similar size will kill each other. Therefore, Flowerhorns command a tank of their own, and don't feel bad, they would only kill a tankmate of the same species. Oddly, they seldom harm other types of cichlids or even Flowerhorns of entirely unrelated coloring, for example orange Jin Kangs successfully kept in tanks with a regular Red Dragon.

Fin Breakage
Nets break fins. Don't use nets on Flowerhorns. Use jars, plastic bags, your hands, ANYTHING but a net!

Cold Tolerance
I have read with interest about Flowerhorns being kept down around 45^o F however I have had no such luck. I have found that raising or lowering the temperature a mere 15^o in a short period of time is terminal for some Flowerhorns. One case was a group of Flowerhorns I moved from 73^o to 87^o in only 15 minutes. I lost one fish in that group of five. I will not err that way again.

Another case took fish from 72^o down to 55^o in short order, and I lost one fish out of three doing that. I will not err that way again.

Disease Susceptability
This is not a problem. Flowerhorns are amazingly durable to most diseases. Oh, sure you can make them sick, but it doesn't Just Happen, you have to abuse them pretty much. Poor water quality is the primary cause of disease in Flowerhorns.

Shipping Troubles
See our article on shipping

Breeding
Breeding Flowerhorns is not really recommended. Mostly this is because the rate of compatibility is so very low, you will injure a lot of fish waiting on a pair to form. When you put some fish together, injuries will occur until a pair is established. Fish will die in the process. Based on what they typically cost, this is unacceptable.

On top of that, because of the fractionation of the genetics of the Flowerhorn, your offspring could be AMAZING or DRAB. I don't see much in between.

Seldom do two nice Flowerhorns produce similar Flowerhorns. This is because of the dominant and recessive traits brought by the earlier generations (cross species) in the "making" of Flowerhorn.

Flowerhorns have the following advantages over other cichlids:

They are relatively gentle with unrelated species. I've kept my Flowerhorn "Bebe" with small gold barbs, Leporinus and Cory catfish.

Flowerhorns are more colorful than many more common species of cichlid.

Most importantly, no two Flowerhorns will be identical. You could own a Texas Cichlid for example, but someone else will have one just like yours.

They readily accept pelleted foods so you don't have to cannibalize goldfish or guppies. This makes your fish healthier because they don't catch diseases from their food. Easier, too, to keep a can of pellets than a fishtank of live food.

They max out at thirteen to fourteen inches so they're comfortable in the common 55 and 75 gallon tanks.

Cool: You can usually tell when they're "young" if they will be quality or not.

Judging Flowerhorns Article on Judging This young fish at right is 2.5 inches long and already shows three of the most important Flowerfish traits; the start of a hump on its nape, a robust red color and a nice row of flowers on the sides. Interestingly, in the smaller sizes, Flowerhorns aren't very aggressive to each other. The fish at right sold for under $300 - it's a double flowered Red Dragon with a great hump, red eyes, lyre shaped fins, and red in the fins like you see on champions. The fish at right sold for under $300 too. It's amazing because it combines finnage, red eyes, electric blue and the start of double flowering. It's gone, so stop drooling.