I love my remora, so much so that I bought another one recently for my 40g.
i also run eshopps skimmers and again, like them so much for in sump use that I bought two.
A 30g is do-able but you really will have to work on a water change schedule. ANd you should have at least 5g on hand at all times in case something goes screwy with the water and you need immediate water. I had a 29g tank and did abotu 6-7g a week. ALso need a couple gallons a week of unsalted water to make up for evaporation.