(Just an Example)
HERE is an article about the Great Barrier Reef Aquarium that uses a 1 time turnover per 24 hours.
HERE is a TOTM that is using 100gph return.
I wish I could find the specific part in his book about this but I may be mistaken for where I read this. I know that I talked with him about it when he gave a coral propagation seminar in Rogers Arkansas about 2 years ago. He also used to talk about this when he had his own section on reef central about 1-2 years ago. Take the info for what its worth. I don't think anyone has the intention of running a system with only one time turnover per day through the sump but accepting the notion that it is possible, I guess is a far reach. I know it was difficult for me to accept until I thought about the basic principles involved in reef keeping. Keep it simple. I included two examples of systems that use this type of low flow through the sump. Maybe someone should contact them and tell them they are wrong eh?