Gary,
Have you witnessed a broad application of hydrogen peroxide into an Aptasia infected tank. At what concentration of hydrogen peroxide did you dose tank. Please explain.
I regularly use hydrogen peroxide on corals & rocks at a 10% solution as a 10 minute dip on the outside of the tank. It is an indiscriminate oxidizer. I have 35% concentrate and it will eat through human skin. Whoever said that Aptasia could not be killed on outside of tank missed the mark. A drop of concentrate applied directly to flesh will bubble it away in seconds. Even 3.5% of the shelf will produce the same results with more peroxide used. If the Aptasia is big, I flush with excess peroxide to completely dissolve organic biomass.
In tank application:
The slime coat on corals & Aptasia inhibit peroxide oxidation. The easiest application is with a tooth brush dipped in concentrate and brushed against offenders. Brush vigorously and reapply peroxide every 30 seconds. Once slime coat is pierced, peroxide will completely oxidize Aptasia. Obviously, if allowed to achieve high density, dissolving Aptasia biomass adds organics into water column.
PS: For algae eradication, hydrogen peroxide is the bomb. When you scrub that Aptasia off the rock, you will have also bleached all algae and pink coralline algae returns or I have taken algae coated rock and brushed or sprayed on with windex bottle and allowed to set for one hour, then flushed off with tank water than returned to display.