My cichlid fish laid eggs on the tank glass. Will they hatch?

It would depend on if the eggs are fertilized or not. If you only have female budgies the eggs will not be fertilized and will not hatch. If you have a mating male with female I would recommend keeping the birds in a quiet location that is low stress. The female bird will care to the eggs and keep them warm. If you find she is leaving them in the open you. An put material in the cage so she can build a nest.

The fry should emerge within 4 days of egg laying. Any egg that turns white or cloudy is infertile and should be removed (if it isn't eaten first). Methylene blue can be used safely to keep eggs free of fungus.

If your Oscar is the only fish in the tank and there is not a male present, then the eggs are not going to be fertilized. With the eggs not being fertile, they will not develop into fish. With this, you can do a couple of things - you can leave them, and there is the potential that she will eat the remaining eggs, or you can also remove them. She may continue to lay eggs intermittently - I would recommend monitoring her appetite during these times as sometimes fish will not eat well while they are guarding their eggs. I hope that helps to answer your question, and good luck!

Cichlids will "lip wrestle" as part of their mating ritual or when acting aggressively. This is normal as long as you have breeding pairs. If they are males, consider separating them or increasing the size of the tank to prevent injury.

Vitamins will not aid in fertility. Being a hybrid species, most male blood parrot cichlids are infertile. Some breeders will use hormone injections, however, this should not be done without the advice of an aquatics specialist.

Breeding discus is not this simple. Placing a male and a female in a tank does not guarantee they will mate. Discus need to pair up on their own. Initially, you will need a group of dis us and them watch them for pairing up. Imce they do, you can transfer them to a breeding tank. Maintain proper temperature and water chemistry. Once the female spawns, you will need to maintain pristine water quality and conditions. After fry hatch, you will need to decide whether or not to raise them with the parents. Eventually, they will need to be moved out to grow out tanks.

That can be normal, yes. You can check the eggs when they are not sitting on them to see if they are viable - eggs that are fertile usually start off very translucent and then become more opaque (darker/more solid color) as the embryo develops inside. (12 days should be enough to see this change.) If the eggs don't seem viable, or the parents stop sitting on them, they can be removed. If they aren't hatched after 3-4 weeks, they are likely not viable and should be discarded. Make sure you offer an extra source of calcium for your female in the form of eggfood or a cuttlebone. This can help replenish the calcium that was used in making eggs and prevent egg-binding (an egg getting stuck) if she decides to lay more.