Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to keep discus [title] Keep a clean tank. [step] Discus fish are sensitive to disease and water conditions. They don't like water changes well.

Ending1: No matter how frequently you change your tank, a large tank will get dirty faster than a small one. If possible, try to keep a clean tank for each substrate you remove. Ending2: If you water your fish once a week on a regular basis, you should keep your tank healthy. [substeps] If your water changes too quickly, keep it clean. Ending3: It is recommended that you have one fish per ten gallons. Make sure the ph level is between 6 and 7; levels below 6 and above 7 will cause discus stress. Ending4: Please stay up to date on their specific needs. Replace normal or natural tap water with aquarium water.

Answer format: ending1/ending2/ending3/ending4