When I have to use a conditioner it is generally because chloramines are in use. Then I use Prime. If you never have chloramines, use the simplest sodium thiosulfate solution, without slime coat junk or metal "removers".
You have no big issue with traces if you use a trace supplement such as Flourish.
Conditioners which state that they "remove" heavy metals in reality do not. They complex them or chelate them or in some manner bind them - that may remove them from the water cloumn by salting them out - in which case they are now in the substrate, where they will be accessible again. Or when the agent which complexes them of chelates them itself breaks down, the metal is back - either in the water cloumn or in the substrate or in the filter with water pouring over it. Removes it how? Matter is not created or destroyed. Copper remains copper, lead remains lead, arsenic remains arsenic.
