cyano - to vac or not to vac

keith gray

I continue to have some cyano issues in my tank. 75 gal with 90 # lr.
Medium bioload and corals. Below are my parameters.
salinity 1.025
ph 8.4
kh - 8
calcium 420
nitrates - 0
phosphates- 0
temp - 80
I know overfeeding can cause an issue, but I only feed once a day and do it slowly as not to lose a lot of food in the sandbed, etc.
I know lack of flow can contribute but I have 3 koralia 3's and 1 small powerhead that I can't remember what it is. So I don't think flow is an issue. I have played with these numerous ways to get ideal flow patterns.
I do a 10% water change every other weekend. This has proved to be the best schedule and work on keeping my numbers where they need to be.
I have a reefdynamics skimmer INS 80 that does a bang up job and a fuge with grape caluerpa.
I suck the cyano out with a turkey baster every week or 10 days and dispose of it.
Would it help to vacuum the sandbed in those spots.
The cyano is not crazy out of control yet, but I would really like to get rid of it.
Last night I got it out and the sand bed looked so damn nice !
I want to keep it that way


Well-Known Member
Kill the lights for a few days to kill off the cyano.
the resume with less duration lights so the corraline/mscros thrive but cyano doen not come back
my .02


could be the TDS on your RO water (if you are using RO water)
check the TDS even if you are not filtering the water yourself...
let me repharse that..... Check the TDS especially if you are not filtering it yourself.


sounds like my nightmare.....small blotchy spots in my 225G.....all parameters are 0-1.....Killed MH lights half of Fri, all of Sat & Sun, blotch's reappeared Monday....and Tues
I siphon it out daily for fear of being over run.....can not for the life of me ...figure this out either

HEYJstdv8....what is repharse
How old are your bulbs, old bulbs can cause cyno (the spectrum will be off) as they get older they enter the red spectrum, the red spectrum is were pest algae thrive.

tangs rule

Active Member
Originally Posted by longislandmike http:///forum/thread/383445/cyano-to-vac-or-not-to-vac#post_3357180
How old are your bulbs, old bulbs can cause cyno (the spectrum will be off) as they get older they enter the red spectrum, the red spectrum is were pest algae thrive.
YUP! ! !
Old bulbs will cause cyano&GHA blooms with near perfect "other" parameters....As ALL types of bulbs age, they begin producing invisible & sharp red spectrum spikes and usually this is the cause (I just changed 6ea 250w, 2ea 175w HQI's and 4ea CF 65w bulbs with all new XM and Coralife ones - $850 worth - ouch! !)....[my hqi were over 1.5 old & the CF were about the same
I was putting it off caus the $$$ - but my CY/GHA bloom is gone now]
Once it starts it is hard to rid - and having good (new) lights won't exactly kill it - but if you remove it, it'll not come back - or at least at a much slower rate. I vaccuum cyano/scrub GHA and then set a trochus or 2-3 on the area (where gha was) over the next few days - it'll be gone 4 good....
And don't think the cheep china version bulbs off ebay are just as good as XM, coralife, current, ushio, hamilton, or other "good" ones......I tried a pair set of 250w 20k HQI's off ebay (new) from some joint, and there's a reason they're cheeper - u get what u pay for! they were worse than the Old bulbs I took out! They only said china on them, the output looked kinda blue (to the eye) but they had HUGE and NASTY red/orange spikes cause within 3 days of putting them in - OMG they had to come OUT! very bad alage explosion - that was 3-4 years ago though, but buy good bulbs to start with!!

keith gray

My bulbs are about 11 months old. I am getting new ones shipped in next week. I currently have 2- 250watt mh (growbulbs). I am replaceing them with 2-250 watt Sout Pacific bulbs. I will see what happens next
I think that should take care of your problem. I would do a water change when you change your bulbs. Do you have any conch nails?

keith gray

I don't have a big cuc really, no conch snails. I have just a few snails and crabs. Probably would not hurt to add some snails and crabs. It seems sometimes crabs knock over or mess with my corals and it pi#$ me off