This question of dosing Flourish after a water change using Prime came up elsewhere, and at the time I discussed it directly with Seachem. Their recommendation was to wait 24+ hours after using Prime before adding Flourish, on the reasoning that Prime would make certain nutrients ineffective. Heavy metals (copper, iron, zinc, nickel, etc) would be affected.
I do not use Prime myself, as I have no need for all that it does, but most conditioners do detoxify heavy metals, and I would suspect by similar methods though I have no absolute knowledge of how this works. I used to wait the 24 hours, but for the past few months I have reverted to adding Flourish Comprehensive, Flourish Trace and Flourish Iron together, immediately following the water change. I have not seen any negative difference, and in fact the plants seem to be better; I am wondering if this is because of the additional CO2 introduced with the water change. I use Kordon's NovAqua Plus conditioner which does detoxify heavy metals. My plants are thriving, and algae is negative, so this appears to be working. I do know that without the fertilizers, my plants begin to deteriorate (I have very soft water), so I must assume the ferts are doing their work.
Seachem also stated that the heavy metal dedtoxification was only sufficient to handle "normal" levels of these metals in tap water, and Prime becomes ineffective after 24-36 hours with respect to any detoxifying (nitrite, nitrate, metals), except for ammonia which it changes to ammonium and this is permanent.
Byron.
