cyanobacteria in hang-on refugium

[bigbubbacain]

I've got a 60 gal. tank with live rock / live sand and the following occupants:

1 Yellow Coris Wrasse
1 Vagabond Butterfly
1 Blue Damsel
1 Sailfin Tang
3 Pajama Cardinals
2 Percula Clowns
1 False Percula Clown
1 Chocolate Chip Star
1 Brittle Star
and various snails and hermit crabs.

I know I've got too many fish and I'm working on relocating the Cardinals and Tang. My water parameters are always good. Ph is always at least 8.2, Ammonia Nitrite and Nitrate levels are always zero. The tanks stays fairly clean of algae, as I only have to scrape every other week.

My problem is the cyanobacteria in my hang-on refugium on the back. It's difficult to control. I've seen other post where users suggest keeping the lights off for a few days to control the Cyano. Can I do this with my refugium? Will this kill my macro algae and all the little critters that are living in them? Should I also leave the lights off in the main tank? The thought also occurred to me that I could turn off the pump to the refugium as well because when the water level drops, it exposes the macroalgae to the air. Is this a bad idea?

 

[rustybucket145]

How much water-flow do you have going through the fuge?

 

[Sk8r]

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1434260&highlight=cyanobacteria
This might help.
Do NOT do lights-out with caulerpa in your system: sporulates, can take out tank. A few strands ok, a lot, no.
pump should never be shut down.
It survives in air as well.

 

[bigbubbacain]

I have a Rio 50 powerhead rated at 260 l/hour. I actually switched from one of the larger Rio powerheads rated at 547 l/hour. I was told that the macro algae could do a better job on the nitrates if the water flow wasn't too fast. Do I need a larger powerhead?

 

[cdness]

I think I have the same issue with my fuge... the water is just a trickle in mine. I am watching this thread for options...

Mine is a 10G tank fuge that is piped into the sump... I was thinking of adding a powerhead to the fuge tank just to spin the water a bit, but I don't know if it will even help.

 

[rustybucket145]

You don't have enough flow. Imagine macro in the ocean.... thousdands of gph flow over it and it still does fine. This really is one GIANT misconception that many people in the hobby have. Get your flow up and the cyano will disappear and your macro will start growing better.

In a low-flow environment the cyano is going to out-compete the macro every day of the week. Boost the flow, the macro does better and the cyano can't hang on. Soon it will be starved b/c your macro will be taking over.

 

[bigbubbacain]

Thanks Sk8r! I looked at the link and saw one of the messages about skimmers. I've got a Red Sea Prizm that's supposed to be rated for 100 gal. Is this skimmer any good or do I need something else? The last time I used Chemi-Clean I lost a few fish, and that leads me to doubt the abilities of my skimmer.

 

[bigbubbacain]

Rustybucket: What kind of flow would you suggest?

I've got 3 Rio powerheads to choose from, the little one is in place now. The other 2 will move:
540 liters/hour
800 liters/hour.

Is 800 l/hour too much flow?

 

[rustybucket145]

How many gallons is your HOB fuge?

 

[bigbubbacain]

I've got the CPR Aqufuge that holds 3.6 gallons.

 

[rustybucket145]

I'd go with the 540 and see how it does. If it looks like it could handle more you could try the 800 but I have a feeling the 540 is going to do the trick.

 

[Sk8r]

rustybucket: +1 on fuge flow: mine shoots into the 20g fuge like a firehose, from a 15 foot drop: hits the cheato and a dune/liverock barrier and slows there. Cheato grows like mad. I take it out by the pound.

Skimmer, next your return pump and lights, is mega-important: 2x the gallonage rated for your tank/system and it should do well. I pull a measuring cup or so of darkish gunk a week from my 54g. I run an EV 120 with a 30g sump/54 tank. So I could use maybe a bit more, but I'm doing fine since I got the critter tuned. A well-skimmed tank is good for everything: look at all that foam the sea throws on beaches: skimmate.
Also in high summer we tend to have curtains open, people coming and going and leaving blinds up, etc, and maybe that stray sunbeam finds your tank in the morning: all encouragement to a critter (cyano) that likes light. So try to fix that too. Everything said here is valuable; and don't underestimate the survivability of cyano: it's been with the planet far longer than we have.

 

[bigbubbacain]

Thanks guys!

Rustybucket: I'm gonna go ahead with the 800, remove the Caulerpa that's covered with the stuff and see what happens.

Sk8r: I've got an issue with the lights. My hang on fuge has it's own light. I've been running the light during the day because it keeps me awake at night. Could this be contributing to the problem?

Is this is part of the problem, maybe there's some kind of happy medium? Turn the tank lights off earlier in the day and the fuge light on, then turn the fuge light off at night?

 

[Sk8r]

My fuge lights run 24/7. I've figured maybe I should give the cheato a brief dark, but I've been too lazy to hunt down another timer. More light would help everything grow, including the cyano: it eats light, carbon dioxide, and water. So you've got a quandry there: there's plenty of that around.
I probably have some cyano somewhere in my fuge, which is a big fuge, so I don't worry. but in a smaller fuge it is an issue. Could you just replace your weed and scrub out? You'd get some back soon, but at least you'd have exported that lot.

 

[bigbubbacain]

Yeah, I guess it's time for a scrub-out. I didn't want to buy Caulerpa, I got it for all the little "bugs" that were in it. That made it hard to pass up. If I can sort them out of the Caulerpa, replace it with Cheato, then the next time I have a Cyano problem I can safely turn the lights out to kill it. Does this sound feasible?

 

[rustybucket145]

Personally.... I'd scrap the caulerpa and go with chaeto only... much easier to manage IMO. You could go dark with chaeto upwards of a week with no harm.

 

[bigbubbacain]

ok thanks!

 

[CraigSlice]

<a href=showthread.php?s=&postid=13115277#post13115277 target=_blank>Originally posted</a> by Sk8r
Do NOT do lights-out with caulerpa in your system: sporulates, can take out tank. A few strands ok, a lot, no.

i just started lights out to take care of some cynao in my tank, and on one of my rocks there is some caulerpa growth, should i turn the lights back on or continue with the lights out?