Cyano coming and going

[blenny100]

Hello all,

Tank stats:

120G w/sump
DSB (4-6") populated with critters/detritovores
Soft corals and 8 fishes
Ammonia, Nitrites: 0
Nitrates ~5
Phosphate = 0.25
Calc: 440
Alk: 7.5
Established about 8 months
8x36" VHOs (approx 750-800 watts total. 50/50 actinic/white)

I am battling cyanobacteria. It is not terrible, but I've noticed that the cyano increases during the day, and decreases (by about 20% mostly on the DSB) during the night.

My sump light is on during the nighttime, and I have macro algae in the sump.

I was wondering if others have experienced this?

I am gradually reducing the food levels in my tank. Currently I am feeding Eric Bornemann's coral food (which is pretty rich). Also, I run an AquaC 120 protein skimmer.

Thanks!

 

[Blown 346]

Have you replaced the bulbs or added a new lighting set up to the tank? Is the cyano forming in th same spots? You could have some dead spots, it will usually form there first.

 

[Abysswater]

I have the same type of events. Mine grows during the day and retracts at night. I have notice that it likes to grow in places where the water is always constant at flow. But not dirrect in the stronge flow from a pumps. There is a few products out there that people here have said works well. I have areas that are low flow and it does not grow there, to me it thrives in areas of contant direct flow. Almost like it thrives on the nutrents in direct flow.

Here is some info that I found. Might help you understand.

http://en.wikipedia.org/wiki/Cyanobacteria

 

[blenny100]

I haven't changed my bulbs or lighting setup since starting the tank. The cyano does usually grow and recede in the same areas.

Any thoughts?

 

[TekCat]

<a href=showthread.php?s=&postid=6656409#post6656409 target=_blank>Originally posted</a> by blenny100
I haven't changed my bulbs or lighting setup since starting the tank. The cyano does usually grow and recede in the same areas.

Any thoughts?

I'd guess that there is not enough flow in these areas.

 

[notoriousB]

I'd second that thought, you probably need more water flow in the areas where the cyano is occurring.

 

[Abysswater]

Last resort if you can't get in is check!


http://www.marinedepot.com/md_viewItem.asp?idproduct=BE1115

 

[piranhaking]

i personally doubt the low flow aspect, because i have a few small areas of cyano and they are in the areas of the highest and most direct flow of anywhere in the tank. I have no phospate and my nitrate is mabey 2 if even that high. My bulbs are only about 3 or 4 months old. I had an issue with it for a while that i thought i had beat with chemiclean but now it is comming back and i have treated it again and it doesnt seem to be helping this time.

 

[roons]

you have dsb? if so start vacuuming it out with water changes, just cause you test low doesnt mean there is none , the tests only measure water born phosphates, this stuff feeds off of it b4 it has a chance to enter the water column...............it has taken me 4 months of doing chemiclean treatments the night before my monthly water change and vacuuming out as much sand as i can , to get a handle on it.....................my chaeto has finally started to grow because the nutrients are no longer being consumed by this crap..........................

 

[blenny100]

I don't think the problem is flow. In one section where the cyano is especially thick (on the DSB) the flow actually starts of "blow under" the cyano, so it looks like a sheet lifting of the DSB.

I guess I'll keep trying water changes and remvoving the stuff by hand.