Aquarium maintenance will vary based on the number of fish, size of tank and filtration but a good rule of thumb is to remove 10-25% of the water in the tank once a month. The water should be taken from the bottom of the aquarium using a gravel siphon. Remember to treat the replacement water

This would depend on a number of factors but in general it is not a good idea to mix goldfish and tropical fishes. The warm water favoured by tropical may be too warm for coldwater loving goldfish.

Yes salt is beneficial to your fish and improves the aquarium environment. Add the salt slowly to a maximum of 1- 2 teaspoons per gallon. Only add salt if you are replacing water and only I ratio to the amount of water you are adding. Don’t add more salt if you add water due to