Yes, Phoslock is vastly superior to alum. I don't see how anyone can put alum into a water body. By doing so you are replacing one pollutant (which is treatable), with another pollutant which, I fear, is not really removable or treatable (I am not an expert on this so this is just my lay person's impression, not a scientific opinion). Phoslock does not harm fish, plants or wildlife. It has never shown any ill side affects at all. It is safe to use in drinking water, so safe that you can treat a water catchment at the same time as you are drawing water for human consumption.
Alum has been around as a "solution" for a long time, (you made me do some research and I was shocked to find that the Egyptians use it as a coagulant in 1500BC ) as far as I can make out it was specifically used to treat phosphorus in 1911. I am not an environmental scientist, my knowledge of Phoslock and it's "competitors" comes from following this company for many years, since its inception in fact, but alum has serious side affects and limitations that Phoslock does not have. You will have to do your own research but here's a place to start. https://www.researchgate.net/post/How_safe_is_it_to_use_Alum_in_eutrified_lake_to_control_pollution This line of enquiry will lead you to many opinions from varying levels of expertise. You will have to judge the veracity of the individual claims yourself, but many at least, are entirely credible and scientifically proven. I challenge you to find anyone saying that there are adverse affects from Phoslock. There simply are none.
If there were no problems with the use of alum and if it was safe and effective, why would the CSIRO have even started researching a solution to a problem that had already been solved. These products are chalk and cheese from a physical point of view. You asked how different they are from a financial point of view, this I don't have an answer for. For me though, the products are so vastly different that it really is like trying to compare the price of oranges with the price of apples. Not the greatest analogy I know, but it is the convention we use and I think you get my drift. I understand that water authorities etc do judge various "solutions" and that cost is a significant consideration, however, from my point of view, and from the point of view of a growing number of people so it would seem, the price of alum is not relevant if you would not put it in your water if it was free.
PET Price at posting:
$1.28 Sentiment: Buy Disclosure: Held
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