Phosphates in RO water but not RO+saltwater @ LFS

[~_~]

So I wen't to a LFS around here and bought some of there RO water, and also bought some of there RO+salt water(they use tropic marin salt they say).

 

So I felt like testing both the water's when I got home with my seachem test kit.

 

The phosphates on the plain RO water was around 0.2 to 0.4 (kind hard to get it exactly right..)

 

The RO+salt water was 0 phosphates.

 

I asked them about this, and the LFS guy says that the reason why there are NO phosphates in the RO+salt water is that the trace elements from the Tropic Marin salt have killed them (or something like that). And since the plain RO water didn't have any salt or any trace elements..it still contained phosphates..

 

Um, so is that true, or is he a dumbass?

 

I tested the water a few times, to confirm the readings as well ;P

[tinyreef]

i think dave mentioned something like this in the Tropic Marin thread. he noted that TM has a 'higher' amount of aluminum than some other salts and this has the affinity to bond with phosphate (i.e. phosguard, etc.). you might want to check with him directly or he might chime in on his own about that. sounds logical actually.

[MrGuyPerson]

In the ionic form, Aluminum is Al 3+ and phosphate is PO4 3-, so it makes sense...