Originally Posted by JDM
From the site:
" It will also detoxify any heavy metals found in the tap water at typical concentration levels."
I don't know if that renders them inaccessible to plants to use, makes them harder to use or does nothing as far as plants are concerned. I wouldn't use fertilizers for a day or two after a change just in case but if it locked them up away from the plants ability to use them for only 48 hours it really won't affect anything in the long term.
When I questioned Seachem directly on this issue, they responded that Prime detoxifies heavy metals so it will negate these in Flourish Comprehensive if added simultaneously. Heavy metals being trace minerals like iron, copper, zinc, nickel, manganese. Seachem suggested waiting 24-48 hours after using Prime before adding Flourish.
I add Flourish the morning after the water change day. I've no idea if the conditioner is still effective or not, and some say this is unnecessary, but I'm in the habit now. BTW, I do not use Prime, but Nutrafin Aqua Plus since that does all I need; it also detoxifies heavy metals, but presumably for no longer than other conditioners like Prime.