Randy,
Since phosguard is used so much in the hobby is there a way that the free aluminum can be taken out of the aquarium water after the alumina takes out the phosphates? Could you use a poly pad (made by poly bio marine)
I've not investigated aluminum removal. I expect that it comes down on it's own fairly rapidly once the source is removed, but I do not have any data to show that. The fact that organsims quickly stop their reaction when the source is removed suggests it goes away, probably coprecipitating with silica and possibly CaCO3.
Very interesting. I just put in a ROWAphos phospate sponge that isn't bassed upon aluminum in my tank and I'm not seeing the shut down reaction that you stated so maybe the ROWAphos type of phosphate sponges are better!
