Feeding and Caring for Goldfish:
Goldfish will not die over a lack of attention, but you can kill your fish from over caring! You can hurt or kill your fish from over-feeding them, overcrowding the pool, as well as changing the water to option.
Be sure to not to over feed your fish, as they will eat themselves to death! Fish needs lots of room, and water should not be changed more than every few weeks.
Feeding:
Goldfish will pretty much eat anything, but it is always best to feed them with prepared fish food. A good brand will give the fish a good balance of salts and minerals. What you feed your fish, is much less important than how much you feed them. Fish will always be hungry, but you should not always feed them.
You should feed the fish according to the directions for the first few days, and see how much they will eat in five minutes, then remove the extra food.
Generally, you should feed your fish, lightly, once a day. If you notice the fish swimming slowly, then you may want to back off and feed them every few days. This is not neglect, as keeping your fish hungry actually allows them to live longer and keep them lively.
Try varying the food for your fish. Try to give them insects, shellfish, or vegetables instead of their regular food.
Space and Capacity:
Your pool is probably overcrowded if you notice your fish blowing bubbles or coming to the surface often. Your fish need adequate room to breathe properly. If you have too many fish in one area, they the fish can suffocate due to the lack of oxygen in the water.
Work out the surface area in your aquarium, so you can apply a formula for stocking fish.
The formula for the appropriate amount of fish would be one fish for every 20 square inches of tank surface. Keep your estimates low, so you have plenty of room for the fancy fish like Moors or Veil Tails.
If you include plants in your water lily pool or tank, this does not need to be deducted from your square footage, because these plants actually work to oxygenate the water. Plants are a great benefit to your fish!
Temperature and Sunlight:
The temperature of your water lily pond or tank needs to be between 50 and 80, with 60-70 degrees as the optimum range. You won’t have to worry as much about outdoor pools in the summer, as the temperature will generally be spot on. As the temperature cools into the winter months, your fish will have time to adapt and will slow down. As this occurs, you should feed the fish much less as well.
Regulating the temperature in the aquarium requires more consideration, and as long as your fish are not exposed to the cold in the winter or the high heat in the summer they should be okay. Make sure your fish are not close to a radiator, as heat deprives the tank of oxygen, and could kill your fish.
An indoor aquarium should receive sunlight for two hours a day, where as an outdoor aquarium should have at least four hours of natural sunlight a day.
How to Avoid Shock when Changing the Water
The biggest killer of fish is shock. You will want to limit their exposure to shock as much as possible. Especially when changing the water in the tank. If you do this incorrectly it can be damaging, if not fatal, to your fish!
When you are ready to change the water in your tank, remove your goldfish, using their old water, to another container. Now you can clean your aquarium, refill it, and let it stand for a few hours before you put your fish back in. This way the water will come to the proper temperature and some of the chlorine will be released from the tap water.
For larger, outdoor lily ponds, you follow the same procedure as the indoor aquariums.
There is a shortcut though for this pond, as you gently spray the water in, add a few cups of hot water. This helps to aerate the water, bringing it to the correct temperature correctly.