hairy cyanobacteria

[clavo]

I am having a problem with what looks like, "stringy" cyanobacteria. I don't think it is hair algae, because it is reddish in color and if I let it grow in places, the "algae" begins to have that film that covers the sand and looks like cyanobacteria to me. My frustration is that my water movement, quality, and lighting are all doing great.

Examples:
Nitrate <5 ppm
Phos (undetectable with Salifert test kit)
Calcium - 400-420
Water Movement--I visibly cannot find any dead spots and besides, some of the stuff grows in area where there is visibly alot of movement in the water.
Lighting--All of my bulbs have been recently replaced
I top off and do water changes with RO/DI water.
I use an oversized Euro-reef for my tank.

The tank (120 AGA) has been up since January 2006. I dont have a DSB, so I do vacuum the gravel and perform water changes every week between 5-15 gallons. From the posts that I have read, I think that I am doing the right things, but each night when I come home from work, I have to mix the top part of the gravel to do away with the "algae". If there is any on the rocks, I get it off with a toothbrush. I do dose with a 2-part calcium system, but well within recommended dosage. Any thoughts on what I can do or what the cause of this stuff maybe?

[Reefbaby]

Welcome Clavo to TR!

Just a few questions first:

1. You mentioned you don't have a DSB, but how deep is it actually?
2. What's your livestock quantity?
3. How much are you feeding?
4. How long did you cycle the tank?

Rather than just mixing the cyano back up into the rest of the tank, you can think about using a canister filter and siphoning it off when you do your water changes.

It could be that you're feeding too much and thus, the bioload is too much for the tank to handle - resulting in cyano breakouts.

[clavo]

Thanks for the quick reply.
I have 1 sml blue tang, 1 sml purple tang, 1 md sailfin tang and about 11 chromis yellow tail blue damsel mix--so 14 in all.

I have about 140 lbs of live rock. My sand bed is about 2-2.5 in. deep.
I feed 1/4 sheet of nori algae per day (usually in the morning) and about 1 frozen cube of spirulina brine shrimp mixed with a few flakes of food per day (usually at night).

Lastly, I let the tank cycle for about 2 months before I started adding the tangs.
The cyano problem is at this point not an epidemic, but I don't want it to get away from me either. Thanks for your help.

[JustDavidP]

It is cyano...which will respirate and create bubbles in the mat. From there, the bubbles lift, stretching the cyano mat with it. If they take to the water column, they settle elsewhere and will grow there.

Check the phosphate in your top off water. Also rinse and strain any frozen foods. Your phosphate readings may be misleading. The cyano, and other things in the system may be using or locking the phosphates and therefore, you have little in the water. It is in the cyano..and other things..that's for sure.

In the mean time, also reduce your photoperiod. The new lights, stronger and more efficient, may be fueling the fire too. Reduce and add a quarter hour every so often until you notice no cyano.

Dave

[clavo]

Thanks Dave. I will try it.

[gwen_o_lyn]

How's it look now?

Where do you have the riser tube set on your Euro-reef? Skim wet.

I would feed every other day too. If you see cyano, you know there is plenty of food in the tank.

If you have tried everything and it doesn't go away, I'd take a serious look at your bioload.