Growing Macro's in Sump?

The Shaman

Premium Member
I was noticing today how much detritus,etc. seems to collect in my sump(10g), and was thinking that it might be possible to grow some macro's there. There is no sand in my sump, but I do have some LR rubble in there and adding some lighting would not be a problem. (In case you're wondering why I don't just add a refugium, short story is that I cannot for awhile.) I was wondering if anyone does/has done this before? If so, what spp. did you use and does it attach to rock?(Can't have any floaters)
I haven't tried growing macroalgae in my sump, but certainly other people do this. As far as attaching the algae to rock, I posted a similar question on another site, and most people responded that they use rubberbands or some such "holding" device, until the algaes holdfasts secure to the rock. This of course assumes you are using an algae that produces holdfasts. Also, I was advised not to band the algae too tightly with the rubberbands, as this might damage the macroalgae.

However, I'm not sure this will help with the detritus that settles in our sumps (mine does this too). My understanding is that macroalgaes don't have "roots" to absorb nutrients from the substrate, that they absorb nutrients from the bulk water through their "leaves". You might need a true plant such as seagrass or mangrove to do this. Either that or some detritivores like bristle worms, serpent stars and such. I'm certainly not an expert on algaes though, and maybe someone with more experience than me will chip in here. :cool:
I've tried to grow several species in the sump: the number 1 problem is that water flow is often too quick.
But i did manage to grow spaghetti algae (Chaetomorphia) there until it got out of control and clogged the input of the sump pump
Thanks for the replies so far guys. The water flow has me concerned a bit as well. I was hoping that if I could get something(Caulerpa, Sargassum) established that, in combination with 24/7 lighting & nutrient load, that it just might work. I can be quite optimistic at times though. :)

I did have some chaetomorph at one time(another victim of ice storm) and it seemed to grow well, but like you, was clogging the intake filter too much.
you could try mangroves. I start mine there, then when they root, I move them over to the refugium. I want to buy one of those "hang on the lip" containers the LFS has so I could make some holes in it, throw some sand in the bottom, and then keep the mangroves in the main tank. They are pretty to look at.

the main problem I encounter in the sump is that when I stop the main tank, the level of water in the sump changes (of course) but this hoses up the algae/mangroves in the sump (some float or move into new locations, or some go horizontal and when the pump comes back on, they have to be reseated correctly).