D2 Biological Solution

[@limesstones]

Hi. Thank you very much for this very detailed step-by-step video for D2 Biological Solution. I saw the photo toward the end of the single gravestone that appears to be a 'before and after' in a one half before and one half after view of the stone; before using D2 and after using D2. Would you think when it comes to grave stones it is generally better to one method or the other (method #1 or method #2) and what about the pressure water sprayer (larger container) is it generally okay to use on most stones, or would a more gentle water sprayer be sufficient. Thanks so much!

[@FollettPCLS]

Linda: I don't think it so much matters the size of the water container as to keep a low pressure to the stream of water. The intent is to rinse down the stone, not to blast it with a pressure water spray -- the equipment shown in the video is all that is required. We used different sizes of hand sprayers simply to indicate that a small or large does not matter. As to pressure, a standard water hose is usually 40 psi and that is way more than what is needed. Often the correct approach to any task is knowing what not to do, and that more is not always better... do less. Either method works, just that Method 2 takes less work but more patience to wait and see what the rains do. We keep going back to the library to check on the results for Method 2. A month after application it is obvious that it is working, but it is not yet quite as dramatic of a difference as where Method 1 was used. But then, if the stone is delicate, such as a sugared marble, then the brushing in Method 1 may be a bit too aggressive.

[@limesstones]

FollettPCLS Thank you for the further clarifying details which do help. I thought perhaps the larger container meant it could deliver a stronger water pressure in the water stream. I do not have a container that large so I wasn't familar with them and how they work. I understand that the composition and condition of a stone, such as an early 1800s fragile gravestone, for example, would indicate that the cleaning approach should be adjusted to address those specific issues and thus rule out using aggressive methods that would work against keeping the integrity of the gravestone intact. Thanks again so much for answering my questions and I'm sure your reply will help others as well.