Use Professional grade video tapes. They cost a bit more than bargain tapes, but are designed for continuous use for long periods of time. This is opposed to consumer grade tapes, in which the actual tape is of a different thickness, and has a different formula for the coating. They are not designed for long term use, will wear out much more quickly, and will leave deposits on the VCR s heads much more easily. Rotate your tapes.
Tapes wear out.
When you consider that they are generally running all the time, it s no wonder. High quality tapes will last significantly longer than consumer tapes, but still can not be used indefinitely. In a typical installation, recording at 24-hour speed, it s a good idea to have a stock of 31 tapes, numbered for daily use. Another benefit of this is you automatically have a record of all events for a month at a time. Check the tape manufacturer guidelines for more information.