There's an entire group of SW folks that have tossed the skimmers for refuges.
This is not just my observation, everyone reports this.

You'll also have better coral growth, the micro algae that give the coloration are better as well.

There's less nutrients stripped out and the macro algae nutrients allow the coral's micro algae to grow very well also.

If you want very low nutrients etc, and have no refuges, then use a skimmer.
But if you want to use biologhical means, then use a refuge or just do an outright planted marine tank and make the tank the filter.

N and P balances with fish waste/food etc are often hard to do, if you remove all the NO3, that's bad for the macros, if you remove all the PO4, that's bad for macros also.

what you want is an easy to manage low level of nutrients that's balanced, fish alone cannot do that effectively over time, the waste and what the plants demands will be different, therefore you have to top off the nutrients suspected of being too low.

You can test to see, use Lamotte or better test kits for this also.
I think doing large water changes makes Marine systems work extremely well.

MBA uses large flow through water changes to maintain the health of their systems and it works better than anyone else's.

Yes, it cost $ to do weekly water changes etc, but it's still cheaper and easier than many other solutions.

No Kalk additions, no dosing various things, no organic build up, no skimmers, no test kits, it makes life simple for smaller tanks, say less than 100 gallons.
A 32 gall trash can to pre mix the water is all that's needed.

Salt for that will run a few $$
200 gal of salt mix runs me about 29.99.
So 200gal/32 gallons= 6.25 changes per bucket

30$/6.25 = 4.80$ per water change which for many will not pay for the electrical bill for a huge skimmer and Test kits etc.

Some might have an issue with a simplified method called water changes due to this cost, but it's not that much really and you spend less on other junk and less time fiddling.

You can let things go a week etc also and still dose and get a feel for things, maybe doing water changes once every 2 weeks, then the electrric cost for a a large skimmer will be that of the salt cost.

Balancing the salt cost vs the added junk and equipment is a very real issue, then you are not bound by excess nutrient build up since a water change addresses it, and Alk and Ca++ levels etc

Economically, you should really look at all the cost and the practical hassle of dealing with all the automation and other crap and keeping it all going.

The simplicity of a water change is difficult to beat.

Regards,
Tom Barr