Guppies are hardy fish that can adjust easily to minor fluctuations in water quality. However, don't allow these fluctuations to become common practice, as they do cause some stress to the fish. The water temperature in an aquarium for guppies should be kept between seventy two and eighty two degrees. A general rule is to wait another thirty days before adding additional fish, because that is the incubation period for most fish illnesses. In addition, test the nitrite and ammonia levels before adding these additional fish. The ammonia levels should return to zero. This also takes about a month. There are a few basic tips that will keep fish healthy. By adding oxygen to the water, the use of live plants helps keep your aquarium balanced and will aid in fish health. The most important factor in growing and maintaining healthy aquarium plants is the lighting used. For a well planted aquarium, it is suggested to use 2-3 watts per gallon of water. The use of fluorescent bulbs is practical and adds a nice lighting effect. While a home aquarium does require regular maintenance and cleaning, it is minor compared to the care required for larger pets. Aquariums are usually less costly, as well. Dogs and cats require regular visits to the veterinarian, vaccinations, flea and tick medications, etc. Last year the purchase of pet toys was a billion dollar industry. There are many different varieties of aquatic plants. Tubers are a type of plant that needs to be anchored by the root to the bottom of the tank. They may be tied or simply buried underneath the substrate in the bottom of the aquarium. There are also floating plants. As their name suggests they simply float in the tank they do not need to be anchored and will not usually require fertilizer. During the eighth week, you can add Aquacultured Coral such as Pumping Xenia, Starburst Polyps and Spaghetti Finger Leather Coral to name a few. Place these corals into the live rock as you did with the previous set of coral. Now you have succeeded in creating your reef aquarium. During the course of the 10 to 12 week mark, you may begin adding your fish to your underwater world.