Actually there's three different types of red macroalgae in there. I thought "kelp" just = seaweed = macroalgae.
The two big bunches to the left and the pieces on the right are some form of unidentified gracillaria. This stuff grows like a weed (even when it was 1.019 - 1.020 brackish - even caulerpa didn't manage that), but doesn't seem to want to self-attach. It's rubber-banded onto rocks. I give it a hair cut every week and then spend 20 minutes removing all the loose bits. The puffers like to take little nips out of it (probably because of the 'pods on it). The little semicircle holes on it are quite cute! Very slippery and deep red.
It's a bit of a pain to keep attached, but grows so rapidly it must be doing wonders for nutrient export. It would be great tumbling in a refugium under bright lighting.
The bunch reaching for the sky nearer the centre is red grape caulerpa -- not caulerpa at all (fortunately). Liveaquaria identifies it as some form of Botryocladia . It's only been in there for 2 weeks, but seems to be growing well, despite being in the shadow from the centre brace (yuk!)
The lowest bunch in the centre is attached to a rock, and may well be another form of gracillaria. Or something else entirely. We'll have to wait and see until it grows higher / I can be bothered to identify it properly. It too is reaching upward fast... it appears to be anchored at the bottom and grows in a helical pattern. It came tied to the rock from the LFS, but it appears to be able to attach by itself. EDIT: The bottom puffer's got his head in it in the second photo -- any IDs?)
Unfortunately this rock also had some well-hidden hair algae -- so on a few occasions I have had to take it out and pick off the "bits". Amazing how the LFS manages these things -- the tank LOOKED (at a cursory glance) spotless -- they probably go through their tanks every morning and manually remove all the hair algae, making suckers like me think everything is clean and growing well. Ah well, the macro is so virulent it is growing much faster than the hair, so no big problem.
I need to get more "green" to fill the tank out, but I'm nervous about caulerpa. I have the one sprig of feather caulerpa there on the right, and will probably leave it at that. I ruthlessly cut growth edges off it every water change, as I am paranoid about it.
The LFS has some sort of green Ulva (lettuce algae) growing in their display, growing reasonably well -- but it reminds me a little of out-of-control bubble algae, so am still weighing up whether to take a piece or not. I probably will.
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