The feature #8 is very important. The lid just twist and open for ease of re-filling the medium.
For your tank size, and you're not into sps, it more than sufficient.
In previous RC "reefkeeping" magazine, there are a few chapters of CR tuning and info etc, you can refer to them.
When I get my CR, this is how I tune my CR with pH controller help;
Day 1 , KH=9.6,
Set pH controller at 6.2, turn on C02 solenoid for 2hours period, measure KH at 2 days later;
Day 3(2 days later), KH=8,
Then it means the CR cannot sustain the KH consumption, I then increased the hr to 4 hours period and pH remains the same, re-measure at 2 days later;
Day 5(another 2 days later), KH = 7.8 ~8 range.
It indicated the CR can sustain the KH consumption since the KH remain stable. Then I fixed this setting. Next I used KH buffer to raise till my ideal approx KH 9.4 range(my preference range).
This setting will remain for the time being, but if you change the lighting regime or increase more coral/clams(or more coralline algae) etc, you will need to check the KH and increase the hrs or drip rate accordingly.
Hope these info on CR tuning helps.