Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
I didn't read Jim's articles, but I say NO. Only use one on a hospital tank, not on a DT. It doesn't discriminate between the good and the bad and is typically undersized anyway.