I ran my 55g skimmerless since day one. It just hit a year this month and I tore it down a couple of weeks ago. I did not dose anything and did somewhat bi-weekly water changes (I would forget a lot though). The display also had a 5" sandbed.

System was T5's and LED blues, large sump with large refugium full of chaeto macro and 5" DSB.

I could not keep SPS in this system aside from Hydnophora. Softies and acans did well in this tank.

BIGGEST problem for me was hair algae....I never got that under control aside from using a sea hare. Not blaming the lack of a skimmer but I'm sure it might have helped in this system since the nutrients were so high.

This tank was just a little neglected since it took a second seat to the MCC tanks full of frags and $$$