6500w of light? I'm sure you mean 65k. and the macros will grow in any range of light that contains PAR if you have enough of it (photosyntheticly active radiation which ranges from 400-700 nm (which would actually be almost all visible light ranges par varies by kelvin. you can grow macro algae under a soft white bulb form home depot, which is no where near 65k. i'm sorry but I think lack of intensity in the fuge was at fault for the macro. (which is funny now that you've changed your diagnosis from clean water, to clean water and the wrong light)
Also i never said you can't keep shrooms under halides, but its not unreasonable to think that he may have light shocked them if they came from lower light. I've cooked a coral or three under my previous set up of 2x250w halide with 220w vho. heres a surprise for you flower, ALL corals are filter feeders (or at least feed organismaly, as in they ingest physical matter, trapping methods vary), Xenia is probably the closest coral to NOT being a filter feeder in so far as it can absorb nitrate from the water by absorbing and releasing water and has been shown by research to be the closest thing to a purely photosynthetic coral.
Either way I'm probably not going to convince you. Which is fine by me as long as the OP realizes how silly the concept is given the situation. If it was a new tank started with all dead rock maybe, but a tank over a year old. come on, I just can't stop laughing.
here is a chart showing the activity level of photo synthesis along the entire visible light spectrum the peaks in blue and red are best but notice plants/algaes can still photosynthesize along the entire wavelength