Firstly on a sad note, my stromb died recently. It hadn't moved for a while, hanging out in the shrimp's cave ... I guess it wasn't getting enough food from my substrate or feedings :( L
Looked in the tank yesterday to find 3 bristle worms all fighting over its eye. At least they were doing their job I guess ...
The other major update this week was that I pulled out one side of the central arch, the zoa rock. It has always had some caulerpa growing on it which I was staying on top of with tweezers, but recently I noticed that the caulerpa was winning over the zoas so decided to take some drastic action.
I first of all pulled what caulerpa I could from the rock while also closely examining for critters. I was surprised to come across these ... baby cucumbers! I had known of one or two in the tank but not this many on one rock. They went straight back in and are hopefully hanging out in another rock.
Having a small tank means no option of introducing a fish to tackle the algae like you could in a larger tank, so I decided to turn to hydrogen peroxide. This is a known to work really well on hair algae, not so well on some types of caulerpa ... but apart from removing and completely boiling/cleaning the rock I thought it was worth a shot.
So after removing any beneficial life I could find, I soaked the rock in a 20% or so H2O2 solution for a few minutes. The next step was to remove as many of those zoas as I could, reducing the risk of die off on the main rock as I soaked it further. As you can see, I had as much algae as zoa, but after pulling a bit more from them stuck these to frag plugs, algae and all.
Once I removed as much zoa mat as I could (and it was bloody tough given the rock, which is extremely textured/nobbly), I soaked the rock some more, and the zoa frags, again pulling as much algae as I could with tweezers. This is what my solution looked like by the end.
I rinsed everything twice in separate tubs of fresh tank water and placed back in the tank, a little fearful of the knock on effect/mini cycle I was going to cause.
Thankfully I have had no signs at all that this has happened, and the rock and zoas both have recovered well. Even the zoas remaining on the rock are opening up again despite having been soaked in H2O2 for quite some time.
As you can see, the frags are pretty much algae free, but there is still a bit on the rock so I think I will re-treat it again before leaving it be.
(bottom right two and top ones here)
So while I wouldn't recommend jumping into using Hydrogen Peroxide without lots of research first, it is a great option for nanos or where you can remove the infested rock easily for treatment. Some people have dosed their tank with it but I don't feel confident in going that route myself given potential knock on effects (eg snails die, some corals badly affected).
I'll also be utilising some of the newly zoa-free rock space for more SPS :D