Regular moss in my Irish moss
Thank you for your question to Ask the Expert.
The best way to remove moss is to remove it my hand or potentially by pressure washing. Here is more information on techniques: http://bryophytes.science.oregonstate.edu/page23.htm
The chemical control options will also kill the Irish Moss, so this method will not work well for your situation and, in general, chemical control is less preferable for environmental reasons. Here is more information on the chemical control of moss: http://bryophytes.science.oregonstate.edu/page24.htm
Please let me know if you have any further questions.