What does ADM say when you contact them? Before tearing out a $1700 sink, I would at least let the manufacturer know I was having problems. Write or call them and ask if they have a solution. If you get no reply, try going to a site where the sink is sold and write an angry review. That often gets their attention.

I don't see an overflow on that sink - that combined with the small grid strainer is a recipe for slow draining because the air can't escape between the trap and the strainer. You see this problem pretty often on vessel sinks.

There are replacement strainers available that allow air to escape more easily. I've also heard of people having good luck with drilling out the holes in the strainer to be bigger.

I think you need to disconnect the bottle traps beneath each sink to see if you have gunk in them. This type of trap, while pretty, is sometimes not as effective as a conventional P-trap. And it is a design that is not even allowed in the U.S. in many localities.

That trap looks like trouble.

Have you tried boiling water to clean out those traps?

Thanks everyone! This is so helpful. I'll try the boiling water next. Failing that, would an easy fix be to just replace the trap with a simple p-trap?

cafftaff-

Substituting a P-trap would be my next move. they're not expensive, and it would be the easiest way to figure out if that's the problem. If you still have slow draining after that, I would investigate whether you have proper venting. Are these sinks a replacement for other sinks that worked properly?

@kudzu9 Thanks. I think that's the route we'll go. Yes, the old sinks were always fine. Just need to find a plumber now. Don't suppose you are based in Chicago, haha!

cafftaff- Thanks...but I'm 2000 miles away 😂

My husband just made what may be a crucial piece of evidence. The sink was originally a single sink, and the plumber converted it to two for the double sink.

I had the same problem. Luckily I found this thread and I've read the solutions from here. Now I know how I need to use it properly. LOL.

@adamhill Not sure if you mean you have the same sink. If so, the company contacted me today and told me I have an old version of that design. They are sending me a new drain with larger drain holes that allow it to drain more efficiently. Fingers crossed it will work.

The sink that I have is something similar to this one. I searched these models on google, and both of the links showed me the same issues. I moved into this house two months ago. I made a few changes, and I decided to install a new plumbing system in the bathroom, including a new sink. I was helped in this question by the best specialists from https://www.wilcoplumbing.com.au/. These guys worked very fast and used the best materials on the market. I think that nowadays it is imperative to use high-quality materials if you want something to last longer.