PDA

View Full Version : GFO Questions


Tigé21v
10/01/2009, 04:54 PM
I still cannot get my cyano under control. Nitrates are 0.1 or lower (Salifert). Phosphate tests come up clear, but there must be some present, because not only the cyano, but also little to no corraline algae growth. However, I have outrageous chaeto growth, almost doubling every week.
I started running GFO again about a week or so ago, about 2 cups of BRS high capacity GFO on a 240 total water volume system. It seems as if may be working a little. But if possible I would like to do something to make sure it is. So here's the questions.
How much GFO can I safely run?
Can I increase the nitrate level (a little) either through increased feedings ( I'm only feeding once every three days) or through vodka dosing, while still running the GFO, to try to even out the nitrate and phosphate levels? Maybe then the other bacteria could outcompete the cyano, since it seems like the cyano enjoys the low nitrate level.

HighlandReefer
10/01/2009, 05:42 PM
Where is the cyano growing in your tank, just on your sand?

Tigé21v
10/01/2009, 05:56 PM
Minimal on the sand in the DT, but pretty much covering the sand in the fuge. In both the DT and fuge, the majority of it is on the rocks.

Billybeau1
10/01/2009, 09:16 PM
Doesn't really work that way. If you think cyno is bad, you do not want to go the next level up. That's what increased nitrates will get you. The dreaded bryopsis. You do not want to go there, believe me.

Sounds to me like you are close. Stay aggressive with the gfo. If your macro is growing like crazy, this will help. Keep harvesting it out and maybe cut your light cycle just a tad.

Good luck

bertoni
10/02/2009, 04:27 PM
Since there's a bit of nitrate present in the water, I suspect the cyanobacteria are not nitrogen-limited. Increasing the flow might help a bit. Is there a macroalga in the refugium?

Fig
10/02/2009, 04:38 PM
Little or no coralline algae growth? What's your alk/cal levels? How old are your bulbs?

Tigé21v
10/02/2009, 07:27 PM
Since there's a bit of nitrate present in the water, I suspect the cyanobacteria are not nitrogen-limited. Increasing the flow might help a bit. Is there a macroalga in the refugium?

I say 0.1, but the tests come back clear. I just always kind of figure there must be a little something still in the water because the cyano keeps growing.
The chaeto in the fuge almost doubles weekly. I,ve been removing half each week because I was thinking that perhaps the lower part of the growth was dying back and releasing nutrients.

Tigé21v
10/02/2009, 07:29 PM
Little or no coralline algae growth? What's your alk/cal levels? How old are your bulbs?
8.0 alk, 425 calcium. the bulbs are less than 6 months old.

Billybeau1
10/03/2009, 06:20 AM
Do you test for or do you know what your magnesium levels are ?

Tigé21v
10/03/2009, 07:02 AM
1440 a week ago. I really think the coralline algae issue is phosphate related, not only because of the cyano, but I'm also getting limited sps growth.

HighlandReefer
10/03/2009, 07:08 AM
What are you adding to your tank?

Billybeau1
10/03/2009, 07:09 AM
Well then I'll repeat what I said earlier. Just stay aggressive with the GFO. Maybe knock an hour off your light cycle and like Bertoni said, increased water flow may help. :)

Billybeau1
10/03/2009, 07:10 AM
Good Morning Cliff. :wavehand:

Fig
10/03/2009, 07:13 AM
I would run the GFO and a Polyfilter.

HighlandReefer
10/03/2009, 07:21 AM
Hey Billy. :wavehand:

HighlandReefer
10/03/2009, 07:54 AM
Tigé21v,

The research indicates that cyanobacteria growth unlike many algae are not limited by phosphate. Cyano growth is limited by nitrogen. This does not mean that keeping your phosphate & nitrate levels to a zero reading using hobby grade test kits does not help. ;)

In addition to keeping your nitrate and phosphate levels low, you will need to keep your total dissolved and suspended organic matter as low as you can.

Like Billy said, you need to keep on the cyano, by scrubbing and siphoning it out of your tank. You will want to keep the debris off your rock and sand also. Old fashion elbow grease is one of the best weapons against cyano.

Cyanobacteria do produce many types of toxins to help fend off other organisms from taking over their territory. Perhaps this is what is keeping your coralline and corals from growing well. Removing the cyano will help. Running GAC will help remove these toxins along with water changes. Running filter bags to help remove the debris in your water column can help.

Tigé21v
10/03/2009, 01:38 PM
Tigé21v,

The research indicates that cyanobacteria growth unlike many algae are not limited by phosphate. Cyano growth is limited by nitrogen. This does not mean that keeping your phosphate & nitrate levels to a zero reading using hobby grade test kits does not help. ;)

I thought I read somewhere that cyano has the ability to fix nitrogen from the water? If this is true, then it would always have a food source, right? Seems like one would need to have phosphate under control to limit its growth?



Like Billy said, you need to keep on the cyano, by scrubbing and siphoning it out of your tank. You will want to keep the debris off your rock and sand also. Old fashion elbow grease is one of the best weapons against cyano.

Is it possible to run the siphoned water through some kind of media and then return the water to the tank, or is it best to discard the water?

Cyanobacteria do produce many types of toxins to help fend off other organisms from taking over their territory. Perhaps this is what is keeping your coralline and corals from growing well. Removing the cyano will help. Running GAC will help remove these toxins along with water changes. Running filter bags to help remove the debris in your water column can help.
I run 2 cups of GAC which I change every two weeks. (I've been using BRS Premium carbon).
I currently am running 2 cups of GAC also. How much more could I add without negative effects?

Tigé21v
10/03/2009, 01:57 PM
Oops. I mean I'm also running 2 cups of GFO also.

HighlandReefer
10/03/2009, 02:03 PM
If this is true, then it would always have a food source, right? Seems like one would need to have phosphate under control to limit its growth

True, limiting nitrogen is almost impossible in a reef aquarium. Keeping phosphate at extremely low levels will not eliminate cyano. Once you have your nitrate and phosphate levels as low as you can get, then this leaves the organic matter in your water column, on your substrate and in your sand and rock. This is what cyano will feed on. The organic matter is what you need to reduce to help control the cyano now.


Is it possible to run the siphoned water through some kind of media and then return the water to the tank, or is it best to discard the water?

A filter will help, but may not remove small DOM in the water. I would discard the water and replace with new.

I run 2 cups of GAC which I change every two weeks. (I've been using BRS Premium carbon).
I currently am running 2 cups of GAC also. How much more could I add without negative effects?

Sounds like you are running plenty of carbon already. ;)

------------------------------------------------------------------------

If you can't control the cyano after you continue removing it and cleaning any debris from your tank for a fair period of time, you could resort to using Erythromycin. IMHO, it would be best to use the Erythromycin after the tank is as clean as you can get it and have removed as much cyano as you can.

bertoni
10/03/2009, 05:42 PM
Some forms of cyanobacteria can fix nitrogen from the water column, but not all. They all can take carbon in the form of carbon dioxide, and will need phosphorus from the water column. Extrapolating from research results to our tanks can be difficult, but cyanobacteria are persistent.