Here is a list of variables that can affect the stain removal process when using Citra-Shield. The desired results will be achieved, and the surface will be clean. The results may be delayed.

  • Drought conditions – Citra-Shield will remove any existing stains; however, it requires moderate rainfall amounts to wash the stain away. In dryer climate or dry weather conditions, it will take longer to remove the stains
  • Shade– The stains will take longer to disappear in shaded areas.
  • Mixed biological stains- There are all types of algae, moss, lichen, mold strains and most areas have a combination of stains and root structures. The more complex the mixture, the longer the removal process.
  • Stain Severity- The longer the satin is untreated the thicker it grows and the more stable the root system becomes. The longer the organism is on the surface the longer it takes to remove. In rare cases (less than 2%) a second applications needed.
  • Temperature- In some cases staining takes longer to remove in cold weather (Below 32’)
  • Non-Biological staining- Citra-Shield will not remove non-biological staining like rust, excess tar, copper stains, tree sap and zinc stains.
  • Wet conditions- Applying Citra-Shield or Citra-Shield plus, the surface should be dry to guarantee full surface penetration. In addition, we need a 12 hour window before a heavy rain or snowfall after application (dwell time).
  • Incorrect mix ratio- Citra-Shield has specific dilution ratios most cases 5:1. In the event the dilution is to strong or too weak (3:1\10:1 etc.), the results will vary.


Here are a few tips to help with the removal process of algae, lichen and moss stains.

  • Trim back any overhang trees, bushes, plants. Let the sunshine hit the affected surfaces.
  • Remove any debris, like leaves, branches excess bird droppings, from roof surfaces.
  • Redirect any sprinklers that hit the surfaces.
  • Keep gutters clean. Overflowing gutters can produce excessive staining on walls and window frames.