I have had good results using it every day, but I do not do the large dose after a WC. I don't see the point in that. If it is gone in 24h, then you should be dosing the huge dose every 24h, so I've never followed the logic on their bottles about the need/timing for what seems like a superdose. I dose in the morning when I turn my lights on, so the highest concentrations are available to the plants right when they begin photosynthesizing that day. If I do a wc later that day, I don't sweat it, because I just add it back in the next morning.
Second reason I don't want to do the megadose...You probably saw my other post on this but I do worry that too much of this chemical could be rough on the fish, not life threatening but definitely irritating. I am serious, if you pick up any bottle of OTC chemical wart remover you will recognize the excel smell instantly - this aldehyde, like most, is corrosive and burns skin so well that is one of its medical uses. Obviously I still use it in my tank and am happy with what it does, but I'm cognizant that I am essentially pouring a strong chemical directly into the nice clean water my fish breathe. And therefore am not excited about pouring 5X the normal amount in on a semi-regular basis when it doesn't make clear sense to me why you would anyway, given that what you want is to keep a stable amount in the water column.
If I was dosing to kill algae, I probably would go up to the megadose amount pipetted directly onto the algae I was trying to kill.