greenhouse sink size?

My greenhouse is being manufactured! My DH is building me a potting bench with a sink. He thinks I should put a big utility sink in, but I want a smaller one to give me a little more work space on the potting bench, and a little more room under the sink so I can put an r/o system under the sink.. Do you think a sink with an interior dimension of 18" x 12" and 8 inches deep will be big enough? The other one I'm looking at is interior 20 x 15 and 9.5 deep. The smaller one has the drain in a back corner. the bigger one's drain is centered

Thanks for any input! Clara

Clara, I would go with the largest sink possible. I actually put a laundry sink in our greenhouse. It is so NICE. Good luck to you.

cheers,
BD :D

Thank you Bruce. That's what we'll put in. When its finished I'll post a pic. I'm planning to paint the potting bench, and stain the top.
DH thinks I should just stain the whole thing and keep it wood. I'm not going to ask any opinions on that because I may not like the answers! hehe

Yes, a laundry sink. Then, get a piece of thick plywood (personally I’d go for at least 5/8” thick) cut to fit over the top - you get a larger sink AND more bench space. You could even make it fit with the rest of the bench to and add a hinge to the outer edge so you can flip the top over to the side when you need the sink.

Personally I don't have room for anything except plants. When I enlarge , or rebuild - or extend - currently I am doing that for the 20th (?) time I get back to a potting bench and a stores area, but they soon get swamped.
I do have a good utility room next to my kitchen with a fine large sink with hot and cold water and a good draining board, all stainless steel , and I sometime bring a bucketful of pots there to wash and sterilise - but more often than not just put a bucket on the greenhouse steps ( my main greenhouse is a pit house , floor 3 feet below ground level) and use that as my bench.