Sound idea but the wrong "holding tank" if you will. The draw back here is the speed of the water flow. In order for the UV
to properly eliminate any possible pathogen/parasite from making it's way into the main, the flow must be on the slow side which would eliminate the sump as a potential QT
. The sump also being an intricate part of the display tanks systems and not easily disconnected, it should not be used in such a fashion given "Murphy's Law".
This would still have a potential risk but I would instead suggest constructing a refugium for this purpose. The flow can then be optimally regulated in favor of parasite control through the UV
and allow the UV
to be the sole source of water return to the main tank or sump. Be absolutely sure you set it up correctly; proper flow, the housing is cleaned religiously and the bulb replaced every 6 months at the minimum. Hard surfaced inverts are indeed a source of parasite introduction and you are wise to QT
them and anything/everything else before adding to the display....