yes they are... but there is a catch... their pure effeciency make them a nightmare. Reef tanks especially I would avoid this mode of filtration. Nitrate factories like a wet dry filter can make nitrates sky high and thus make algae flourish and fish/inverts under stress.
210 Gal Reef w/ 55 Gallon Sump/Fuge, 125 Gal Fish Only, 65 Gal Seahorse-29 Gallon Sump, 55 Gal FOWLR, 54 Gal Corner FW Community, 20 Gal Nano FOWLR, 55 Gal Piranha, 29 gallon QT
"All the yellow tangs and clownfish in the world can't save you now! hahahah" Peter from Family Guy