Being a fish parent can be time-consuming but is totally worth it in the end. Although some kinds of fish are harder to keep than others knowing your space and time limitations as well as the basic requirements when picking out your new fish can make everything easier for you in the long run. For instance, if you don't have a lot of time to invest in cleaning and caring for your fish buddies a saltwater tank is probably not the right choice for you. Along with that same vein of thought, neither are angelfish because of their heating and tank size requirements.
By far the most important rule to follow when making the decision to become fish parents is "1 inch of fish per gallon of water in your tank." The 1 inch of fish refers to its estimated length at full maturity. Buying goldfish that are one inch now and putting them in a ten-gallon tank is not going to turn out well later as most goldfish continue to grow throughout their whole life. A standard 10-gallon tank is not recommended for goldfish according to this handy goldfish to tank size calculator. Although it is still possible to raise goldfish in this environment it will take a lot more effort regarding cleaning the tank and maintaining balanced ph to keep your fish happy and healthy.
Kimberly Lawton
Another important rule to follow when setting up your new fish-friendly environment is "set up the tank at least 3 to 4 days in advance to buying your fish." By setting up the tank in advance to getting your fish buddies it allows for an aquatic ecosystem to begin developing as well as a test period for all tank accessories such as the heater, filter, and thermometer. According to the sales associates at Petco, I have spoken to recently the time period is a minimum and the closer you get to about a week to eight days the better it is for introducing fish.
A related rule to allowing the aquatic ecosystem to develop is to introduce fish in pairs. Introducing smaller quantities of fish over an extended period of time is supposed to drastically increase the likely hood of the fish adjusting easily into their new home. When introducing new fish in general it is good to keep them in pairs as a fish being introduced on its own is more likely to be bullied by established fish. The other perk to introducing your new fish buddies in pairs over an extended period of time is that it allows for the aquatic ecosystem to stabilize and develop further which will increase the likelihood of your new fish friends thriving in their new home.
For more information on the fish species mentioned or tank sizing please follow the links.