Try also to place the angelfish in a tank that is tall. Mature angelfish can grow up to a foot long from their dorsal to their anal fin, meaning you’ll want to accommodate their unusual length.
If your water isn’t in the ideal pH range, a de-ionization filter or reverse osmosis (R. O. ) filter can do the trick. These are usually attached to your main water supply, and can run from fairly cheap to incredibly expensive. They are, however, effective. Try not to use chemicals to alter pH if at all possible. Chemical pH solutions alter the alkalinity or acidity of the water much too drastically, something your angels are sensitive to. Angels may fail to breed or, worse, die off if the pH swings too drastically from one extremely to another. Ensure that the aquarium water pH doesn’t change more than 0. 2 per day.
Keep in mind the tradeoffs of different water temperatures. Warmer water is arguably better for angels’ immune systems, whereas colder water increases their lifespan.
Do at least 50% water change each week either as part of regular cleaning activity.
Give your angels 3 to 5 minutes to feed on any food you give them. Any food that hasn’t been eaten after 5 minutes should be removed from the tank to promote clean water. If introducing a new kind of food to your angels, don’t feed them at all for one or two days. Then, when you do introduce the new food, provide enough for one or two bites, supplemented with regular food. This should be enough to get them excited about the new kind of food. A regular diet may consist mainly of dried flake food, supplemented with brine shrimp and blood worms. Live food, apart from brine shrimp, isn’t recommended for angels because of the chance of disease.
Females tend to be more round while males tend to be more angular. Female Dorsals are held slightly backward, while male dorsals are fully upright, at almost a 90 degree angle to the head bump. Females tend to hold Ventrals closer to body, while males hold ventrals more erect Females have a more smoothly sloped head, whereas males often have a distinct bump on their heads.
In the spawning tank, provide a surface for the angels to deposit their eggs on. A spawning cone, spawning mop, or simply a piece of slate are items breeders often choose. Angels have also been known to lay their eggs directly on the water filter, for example.
Raise the temperature a few degrees if it’s currently under 80 °F (27 °C). Do a 75% water change, being careful to condition the water and make sure the pH and softness of the water is close to what the angels are accustomed to. Feed them a bit more than usual with high-quality freeze dried food. Give them more security by adding additional plants, spawning mops, or other fibrous, decontaminated props. Try a larger aquarium if your tank is at or below the 20 gallon (75. 7 L) mark. Place another angelfish or another breeding pair close to, but still separate from, their aquarium. Sometimes, the sight of another angelfish will get them breeding.
As the breeding pair raises their fry, continue feeding the breeding pair as before, taking note that they may not be as hungry. Remove any unwanted or uneaten food immediately after feeding and take pains to ensure the water quality is high and uncontaminated. Occasionally you get a pair of angels that eat their fry. When this happens, you have no alternative but to remove the cone or slate with the eggs to another tank containing identical water and raise them artificially.
