I had the aquarium for a few years with live sand and live rock, everything was going great till I had several tank crashes. I had the aquarium sitting in my living room for the last 1 1/2 years, just sitting. no life no lights, no water circulation. when the water would start to evaporate I would always refill with tap water to keep the seals from drying out and the keep the rock and sand wet.
About 2 or 3 months ago I turned everything back on. and let it circulate and turned on the lights for 12 hours a day. pumps, powerheads, the whole bit. when I tested the water at that time it was surprising.
ammonia was 0 nitrites 0 nitrates 200+ salinity 1.027 temp. with no heater was 73*.
during this period ( the first month) I rearranged the rock and kept stirring up the sand to clean the sediments and re-level the sand.
then after a month or so I let it run...lights on water circulating and all that. that brings me to my current spot.
about 3 or weeks ago I went to LFS and purchased a 12LB live rock and set it in the middle of my tank. very soon after that the tank started to cycle and the brown algae was everywhere. the day before I went on vacation Aug 5th, I turned off the lights and was gone for a week. when I came back the tank was spotless of brown algae. but my refugium where I have green algae (chateo) growing I left the LED light on. and that was brown with algae.
two days ago I did a 30gal water exchange. and have CUC in the mail on its way.
I haven't checked the water since I did the water change I wanted to give it time to circulate, I will check it this afternoon.
hope this helps a bit, let me know if you need more info.