Cyanobacteria in perfect water?

[Lt. Hotpants]

Hello all,

I have a 75 gallon system set up with some soft corals and a few easy to keep stonies. The water tests show zero for ammonia, nitrite and nitrate and a ph of 8.2 and i'm lighting my tank with 4 watts per gallon of PC (for about 10 hours/day). I use RODI water and I have a refugium with caulerpa that i'm lighting 24/7. I feed my corals phytoplankton and this stuff called 'reef roids'.

Recently I have had quite the cyano bloom (mostly brown with a little green in some spots) but like i said, my water is perfect. So what's the deal? Has anyone tried this 'reef roids' stuff? How about the phytoplankton, can it cause cyano?

any advice would help, thanks!

[Lt. Hotpants]

[zoomfish1]

First, Welcome to Reef Central. Sorry, no banner.

Second, in order to help, we need more info. Need to know what the Phosphates test at, what is you calcium and alkalinity?

These are the parameters that will show why you have cyano. The ones you listed are mainly for cycling tanks and initial testing. Also, what is the sg and how old are the pc bulbs. All these things will play a part.

Another factor is most all tanks go thru this when they are new. How old is the tank?

[Joshua1023]

Also keep in mind, depending on which test kit you have phosphates will read zero when they are really not. Cyano has a tendency to build up in areas of low flow. I think its not because of the flow itself, but because these areas allow food and other detritus to settle and rot. These will be areas of high phosphate that is not released into the water, but rather quickly absorbed and used by the cyano to prosper. Once the cyano "blankets" the area that rot is trapped under it feeding the red devil.

[blackheart]

no water is perfict just so you know and cyano grow in dead spots also if there are any number of impurities in the water. But if i where you i would get a phosreactor and put rewa-phos in it. Then up your flow this will be a good start

[Lt. Hotpants]

good insight thanks guys

it's actually pretty funny, the cyano is 'blowing in the wind' so the flow isn't a problem, and the PC's are only a few months old. The tank is i think in it's 3rd month, so it's pretty new.

i haven't tested any of the fancy stuff yet, but i suppose i'll drop by the lfs and get some of those test kits.

this cyano stuff isn't particularily harmful is it? I'll attach pics of the tank later so you can see what i'm dealing with.

[Angel*Fish]

Must have the banner ! Welcome!

To Reef Central

[blackheart]

when you do water changes try to suck most of the cyno out of the tank you will notice that it is not hard to suck off the rocks or sand bed.

[dippin61]

actually, its quite a myth, that cyano only grows in low flow. I have had, and still do have a very small patch, that grows right in front of my seio 1500's flow. When i say right in front, i mean less then 6 inches from the direct flow.

and since you say its brown, are you sure its not diatoms, or dinoflaggelates?

[Joshua1023]

Yeah, I've heard a thousand opinions on the subject. It does seem to go nuts from phosphates though. I beat a bad outbreak of it recently. Some Phosban in a media bag and it did the trick.

[Lt. Hotpants]

Here are some pics:

[IMG]http://i18.*******.com/32zopab.jpg[/IMG]


and a closeup
[IMG]http://i9.*******.com/2l8cfb8.jpg[/IMG]


I'm not sure if it's diatoms dip, what do you think?

[Joshua1023]

cyano

[MCary]

Whenever I had cyano problems it grew on new sand or refugium mud. It would form a nice thick slimey crust on top of the sand which was easy to siphon off. Then suddenly it was gone. Not a trace. I bet it eventually goes away.

Mike

[dippin61]

yup.. definitely cyano. try and not to mix it up into the tank, and siphon it out with a water change. it comes up pretty easily.

check your phosphates, they might read low, because the cyano is eating up most of it as it is created. you might want to try and throw in a bit of phosphate remover in a media bag for a few days, and see if that helps.