Precipitation of chemicals other than Fe

Hi folks,

I have a dumb question for the chemists on the list.

I'm aware that Fe EDTA slowly precipitates out of solution in PMDD under 
certain conditions if stored for too long. 

My question is do the other chemicals in the PMDD mix precipitate out of 
solution or degrade prior to their addition into a fishtank? If so which 
ones and under what conditions?

I ask this becasuse I'm thinking of making my next batch of PMDD with the
Fe solution seperate from the rest of the ingredients

Any responses much appreciated

James Wong 
In sunny and warm Sydney.