When should I clean my filter after using Pure+ Filter Start Gel?

If you have a brand new filter you can leave it for the first few weeks, as with any new filter, to allow the gel to coat the surface of the filter media and circulate around the pond.

If it's an existing filter that you have a cleaning regime for, then leave it for around a week after dosing PURE+Filter Start Gel and then just carry on as normal with your regular maintenance. The gel will coat the media and circulate around the pond and within the filter.