Not sure if I am winning or losing the battle. They are still growing but seem to be growing slower. Those that are high in tank in areas of over 250 PAR seem to be struggling to grow staying small and white while ones lower in tank or in shadowed areas seem to be growing faster and have green tips. The urchins seem to be doing nothing, I can' even find them day or night. I'm wondering if they died for some reason after a few days. I don't believe there has been much spread of them just re-growth in same areas. I guess I'll keep up the pruning every two weeks for a few hours and see what happens. I probably need to start back to feeding heavier to get phosphate up to see if that helps, right now I'm only .006ppm.