FAQ: If a product contains EDTA, and since EDTA is amine based, will such products cause the same regeneration issues with Seachem Purigen® as occur with amine based slime coat products?

The type of amine (tertiary, secondary, etc) is immaterial to the issue. It is the specific slime-coat chemical formulation of certain competing slime coat products that causes them to bond to polymer based resin materials in a manner that is highly resistant to oxidative destruction (via chlorine regeneration). If such a slime coat product had no amine as part of its chemical makeup the situation would merely be annoying, however the amine can undergo partial oxidation to a chloramine while still remaining bound to the resin via the slime coat material (likely through non-covalent interactions). It can then be slowly released back into the water through normal chemical breakdown of the slime coat material on the resin over time.

Although this phenomena exists with any polymer type resin (not just Purigen®) it is particularly acute with Purigen®, because Purigen® predominantly and selectively binds and removes amines (whereas other resins indiscriminately bind amines and other chemical groups). So the point is, it happens with all resins, but it happens more with Purigen®. However it is not merely the fact that there is an amine present since Purigen® removes a whole host of organic amine based nitrogenous waste and this is no issue at all since in those cases since those materials are readily oxidized and "burned" off the Purigen®.

So, to answer your question, EDTA is not of concern in this situation as its overall structure is quite different from the amine based slime coat products (although we can't say what the differences are exactly since those other products are not ours and are proprietary). What we can say is we have never encountered this phenomena with EDTA based products nor have we encountered anecdotal evidence to suggest otherwise.