Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Small but very good quality

This product is well made and provides a very fine and accurate control over the opening at the bottom, very good for small spas. It has few severe design problems though:1. Low capacity. The round head is a float and does not hold tabs. You can fill tabs only in the vertical tube and the capacity depends on your rate setting. I am using setting of 2 (low rate) and could fit only 7 small tabs.2. Bottom feeding. When you insert new tabs at the bottom, the existing wet and half consumed tabs are pushed to the top and the new ones are being used first.3. Tedious to open and refill. You need to turn the bottom 10-20 turns to open and close. The opening is small so you need to insert the tabs one at a time and make sure they are oriented correctly.This similar product solves issue #3, it has a removable cap at the bottom http://amzn.com/B004WQ9QH6