Problem: Article: To make a bottle ecosystem, you will need an empty 2 quart (2 liter) plastic bottle. It is best to use a clear plastic so that you can see inside the bottle and make observations. Cut off the top of the bottle, about 2 inches below the neck.  To ensure your cut is straight, you can put a piece of masking tape around the bottle and then cut along the edge of the tape.  Ask an adult to help you cut the bottle. Use a pair of scissors or a utility knife to cut all the way around the top of the bottle. Set aside the neck of the bottle with the cap for later use. Use a small garden shovel and add 2-3 inches (5-7 cm) of potting soil to the bottom of the bottle. Lightly tap the soil with your hand to help it settle. Make sure you do not press too hard because you do not want to pack the soil tightly. If desired, you can add ½ an inch of pebbles to the bottom of the bottle for drainage. This should be done before adding the soil, but is optional. The depth of the holes will vary depending on the type of seed you are planting. It is recommended that you start by planting green beans. They are hardy seeds that should grow easily. Read the directions on your seed packet to know how deep to make the holes. Use your finger or a pencil to make the holes in the soil.  If you are planting beans, the holes should be 1 inch (2.5 cm) deep. Make the holes near the edge of the bottle. This way you will be able to easily see the roots growing. Once you have dug the holes, place one seed in each hole. You should be able to fit approximately 5-6 plants. Cover the seeds with dirt. Aside from beans, you could also try planting a variety of herbs, such as mint, basil, and oregano. You could even grow root vegetables, such as carrots or potatoes. Just make sure you provide enough soil for these plants to take root. Then, place two pinches of grass seeds on top of the soil. Lightly cover them with dirt. If you would like, you can also try adding insects and worms to the ecosystem. Prior to sealing your ecosystem, you need to water the seeds. Sprinkle water into the bottle. You want the soil to be damp, but not soaked. Let the water seep into the soil and then sprinkle a bit more. You want the water to fully permeate the soil. If you tilt the bottle and water runs up the side, you have too much water. Now, take the top of the bottle with the cap and turn it upside down. Place it inside the ecosystem so that the neck and top of the bottle are hanging a few inches above the soil. In order to hold the top of the bottle in place, and to seal the ecosystem, you should tape around the edge of the bottle. This will attach the top of the bottle to the base. You will no longer need to add water to your bottle ecosystem. Now that the ecosystem is sealed, you should place it in a sunny spot. For example, a windowsill is a great place to keep your bottle ecosystem. The location should receive indirect sunlight for most of the day. You can also add a label to the base of the ecosystem with the date and identifying number. This way you can record notes and compare it with other bottle ecosystems that you make.
Summary: Cut off the top of the bottle. Add soil to the bottle. Create small holes to plant your seeds. Place the seeds in the holes. Sprinkle grass seeds on top. Water the seeds. Turn the top upside down and place it inside the base. Seal with tape around the edges. Place the ecosystem in a sunny spot.

Problem: Article: If you clean it all at once, you will lose parts of the healthy bacteria. Use the siphon around your gravel to remove the waste and other matter.
Summary: Use an algae scraper to remove any algae from the sides of the tank before you change out the water. If the filter is dirty, clean out part of the components at a time. Siphon out 10 to 25 percent of the water.

Problem: Article: Both tasks are common in the real estate world but each one is used for a different purpose. Estimates are more general calculations made when more exact calculations are not necessary. Estimates are often prepared for the purpose of putting a home on the sales market. Estimates can be made by anyone and are often made by real estate agents themselves. On the other hand, appraisals are more exact calculations of value and take into account a number of scientific factors. Appraisals are often required for tax and loan purposes (e.g., to figure out the tax liability of a home owner or to figure out what type of mortgage someone will need). Appraisals cannot be conducted by anyone and must be completed by trained individuals. Always make sure a property appraiser is licensed or certified by the state to perform real estate appraisals. While state licensing and/or certification isn't always an indication of quality, it ensures that an individual has met certain standards and is authorized to perform property appraisals. Some states do not require licensing to perform real estate appraisals.  At the state level, there are two types of property appraisal licenses: the State-Certified Residential Real Estate Appraiser would be the minimum license to consider. If it's a typical residential property you want appraised, you will want a State-Certified Residential Real Estate Appraiser, as a minimum qualification. Don't be afraid to ask an appraiser for a copy of his or her license. Once you get a copy of the license, it's a good idea to check with the government agency which issued the document to ensure the license is active and in good standing. Furthermore, you can view the U.S. National Registry at http://www.asc.gov and verify whether the appraiser is registered and eligible to perform appraisals. Many excellent real estate appraisers carry a professional designation. The most widely known industry designations are the Senior Real Property Appraiser (SRPA), Senior Residential Appraiser (SRA) and the Member Appraisal Institute (MAI). These designations are issued by the Appraisal Institute, and demonstrate an appraiser's commitment to continuing education and ethical standards. Ask what their experience is working on the property and neighborhood you are looking to get appraised. Appraisers who do a lot of their work or live in a particular area often have a deep knowledge of property values in that area. Additionally, they are more likely to know how "neighborhood variables" such as school districts and fire departments affect the property values in the area. Although years of experience does not necessarily indicate quality, there are certain benchmarks quality appraisers will have met. It usually takes about five years to get a good working knowledge and competency. If you find an appraiser in the yellow pages, you might not have much information about them. It can be useful to crowd source people in the industry. Ask a lender, real estate agent, attorney, or accountant for an appraiser they have used in the past. You'll still need to inquire further into their qualifications, but finding someone who has experience with the appraiser is a good start. You can also use the internet to find information about an appraiser's credentials, customer experiences, and history of complaints. For example, in California, the Department of Consumer Affairs, Bureau of Real Estate Appraisers has a search function on their website. Using the search function, you can find information about any licensed appraiser in the state.
Summary:
Determine whether you need an appraisal or estimate. Make sure they are licensed or certified. Ask about their professional designations or memberships. Inquire about their experience. Ask around for references.