So algae. How frustrating is this stuff. Short answer? Very.

We did a bunch of research, and the prevailing wisdom says that there are a few different causes of algae growth. Phosphates, Nitrates, lack of filtration, lack of circulation, not enough competing life (macro-algae in the refugium) and lighting cycles.

We approached solving our problem in roughly that order. Nitrates were (and have been) basically non-existent for a very long time. Even a fish (snail, crab, etc) dying doesn’t introduce any significant spike just simply due to water volume. Phosphates are usually introduced when you use tap water (not RO/DI), don’t buffer your added water properly, or similar. We tried just using store bought RO/DI water for awhile, made sure we were buffering properly, and eventually, added canisters in the sump that have phos-ban in them to filter that out. We’ve not had any measurable phosphates in quite some time.

Our filtration and circulation problems were solved when we upgraded the sump/pump and refugium, so that is no longer a problem. We have a big ol’ blob of macro algae in the refugium that is very healthy, and growing rapidly. In fact, we may very well need to prune that regularly in short order, since it is starting to restrict water flow in the refugium.

And after all that (which was a several months long process of trial and error), we were still getting significant growth when things were left untended (meaning, we weren’t scraping rocks daily or at least every few days).

All this time, we were essentially assuming that our lighting cycle was correct. We apparently hadn’t done enough research. We were doing roughly 12 hours actinics, and 12 hours main lights, with no dark cycle at all. Apparently, a more “normal” schedule is roughly 12 hours totally dark, 12 hours actinic, and 8-10 hours full light. So, after fiddling with timers and power strips and such for a day or so, we now have the following cycle:

11am – actinics turn on
1pm – main lights turn on
9pm – main lights turn off
11pm – actinics turn off

Since doing that, all the soft corals in the tank (mushrooms, leather, polyps, etc) have all blossomed and starting spreading, and the algae is no longer measurably spreading. With a few more weeks of being diligent with scraping it off and filtering it out, and I think we’ll be rid of it.

I’m going to throw a few more pictures in the gallery of the way things look now, and I will link to that once I have them up. Looking really good.