I do a 20% water change every week ,it is not really alge bloom it just in one rock and its macro.

welcome to the reefing world lol (jking)so heres the thing we all have tough decisions and yours prob is to lose your mushrooms or get them scraped and put them somewhere else and then kill off the grape. another idea is to scrape what you can and epoxy the area so no further growth can happen if theres no nutrients then theres only one other source for food and if you block out the light then wha la ;)

Remove the rock and place it in a dark sump or circulating bin of water until the algae dies. In my experience mushrooms can survive longer in the dark than caulerpa. But if you're worried you can always cut some of the mushrooms off of the rock to leave in the tank. That is how I rid most of my tank from that nuisance algae. The last little bit of it I plucked out with tweezers. FYI I don't keep any of that crap anymore. Not even in a refugium. Chaetomorphia and gracillaria are much less invasive.

I had a similar problem with a small rock that had zoas on it.
I know it really made a big difference when I started running GFO.

You'll find it doesnt grow back nearly as fast once you do manually remove it.
however, i think you might be stuck with it as long as you want to keep the 'shrooms.

I found out nice they get thicker it is easier to remove them from rock

Hi did you end up getting rid of it all? I have the same problem right now and its really ****ing! :twised:

if your tank is big enough, get a foxface.

Yeah, grape caulerpa (what you have) really gives macro algae a bad reputation. I'm not sure which is worse - valona or grape caulerpa :P.

If you're intent on keeping the rock 'live', as MarkoD suggested, try a foxface. To add to that you can also try to find and buy a few lettuce nudibrachs. They're a type of sea slug that sucks the 'juice' from caulerpa and uses it for photosynthesize in their mantle. I've never used either fish or nudibrach so I can't say how effective either type is.

The sure fire way is to throw out the live rock that has the grape caulerpa growing on it. If you want to re-use the rock, let it dry out thoroughly in the sun for 3+ months before attempting to introduce it into your tank again.

You can always save your blue shrooms by chipping off as much of them from your rock and transfer them to unaffected rocks in your tank.

I have the marine atlas by Baensch. I do not think it is the newest version 1994. But it has a very interesting section on Caulerpa. I like caulerpa, so I have never really tried to get rid of it. I guess you could say I am a quite bias when it comes to macro algae. It has so many interesting biological functions in a reef. I have also read that no healthy reef is without caulerpa or a similar species. Never the less here are 2 suggestions from the book and one of my own.

1. Berthelina Choloris (DALL, 1918) was suggested to be a bivalve that specifically targets and eats caulerpa spices.

2. Since caulerpa is essentially one giant cell some species can bleed to death. The section states that the algae creates wound plugs when fish nip and eat the algae to stop it from bleeding to death. The section goes on to suggest applying pressure to the stolon (the tube that has the roots and leaves coming out) to create a wound plug before cutting the section. It might be possible if you spinkled some kalk powder on the caulerpa out of water it might burn holes in the algae without the force to make the wound plug up. Possibly causing the algae to bleed to death.

3. You might also try Hydrogen peroxide. The full strength stuff they sell at garden stores can be pretty lethal to certain kinds of algae.

Tim, I'd recommend testing your phosphates and before you do anything else and try to pinpoint what's fueling it's growth. I suspect that over feeding or detritus in the rocks are the contributors. I have an Elos Phosphate kit if you need to double check your numbers.

Even if you think it's completely gone, it might come back if there is still a nutrient source for it.