I did the fifth dose two nights ago and turned off the lights. This afternoon, the lights had been off for two and half days. I thought that making the GHA further weak with darkness, might help AF work better.
Anyways, turned on the lights at noon (GHA definitely looked weak) and did a 50% water change. Vacuumed the gravel, siphoned floors of some sections in the sump and replaced old media with fresh GFO and GAC in reactor.
Tonight will be my 6th dose. I have some loosely held GHA in hard to reach areas of the rocks. I hope to see them gone soon.