Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to decrease aquarium algae naturally [title] Test your water. [step] Checking the parameters of your tap water is always a must any time you are having some sort of biological issue with your aquarium. Look for high nitrates, nitrites, and ammonia.

Ending1: Monitor your water while you are testing, and change your filter every couple of months. [substeps] You can test your water once a month for the moment and then use a small pump to just stream water up the filter to your tank. Ending2: [substeps] If you see rare and interesting substances that are hard to remove, go to an aquarium store to purchase some test water. Many stores contain test water and are offered at a discounted rate. Ending3: These will usually be indicators of the cause of your brown algae bloom. Chemicals in the tap water itself, such as phosphates, can also increase algae. Ending4: Any nitrates or ammonia that are present in your water should be avoided, since they are highly flammable and might contaminate your water. You can obtain a chemical tap water test kit from an aquarium store.

Answer format: ending1/ending2/ending3/ending4