GFO and Brown Cyano

[Reefsi]

So about 2 weeks ago I posted a thread about my new tank having a cyano/diatom outbreak, only after being setup for 3 days. The cyano came about the day after I started up the GFO. About 4-5 days went by and the tank was perfectly clean with no evidence of any cyano. I measured every parameter of my tank for the last 3 weeks. PO4 highest point was 0.14 the 2nd day the tank was running, since then the highest reading was 0.03. I measured 20 times with Milwaukee and a Hanna checker. So last night was the night it hit 0.03 and I thought I would change the GFO(I know 0.03 isnt too high but I changed it). So I changed the GFO adding a little less than 2 cups of the High density GFO from BRS(I have a little over 300 gallons total water volume). Today BAM brown cyano.

The first time I added the GFO to the tank I will admit I poorly rinsed it. The second time I added the GFO(last night) I rinsed the crap out of it. Rinsed for 20 min. with water making sure it was clear. I then put it in the reactor and thew a filter sock over the return back to the sump.

Now this cannot be by coincidence. I have done some reading and have found people with similar findings. I also read that cyano, unlike other algae, have the ability to use DOP.

FYI: All other nutrient parameters have been 0's across the board since the cycle. CA:410 Alk: 2.7 me/q Mg: 1250 PH: 8.10 SG: 36.4 ORP: 351

Whats your guys take or philosophy behind this?

 

[HighlandReefer]

Iron in the water column can increase growth of algae, cyano & other pests. Whether or not the GFO is causing a problem with the cyano is debatable without testing the water for the iron levels. Salt mixes add iron and so can calcium carbonate rock and sand. Foods can add iron. So there are a lot of iron sources other than the GFO. Since running a test on iron can only be completed at a quality lab, it is unlikely to go through testing.

If you're concerned about the GFO adding iron, I would suggest adding a filter bag after the GFO to catch small particles of the GFO that may escape. The smaller the pore size of the filter bag the more GFO particles it will collect. You can buy filter bags pretty cheap down to very small pore sizes.

Keep in mind many additives you buy that are for micro-nutrients contain iron as well.

FWIW, the coral need iron for their growth and their symbiotic cyanobacteria imbedded in their tissues. All living things need iron, so you can't eliminate iron from your system completely. It's tough to prevent free growing cyano in your tank which can acquire the iron easier than the cyano in the coral tisses.

If you have a shallow sand bed, clean it at least once a week. The shallow sand beds provide nutrients to the cyano that grow on it.

 

[Reefsi]

Thanks for the quick response. Yes I do have a shallow sand bed and do clean it often I try to stir it up as much as I can. I also have nassarius snails that help with this. They only thing that makes me believe it is the GFO is because my tank was 100% dead going into this. No live sand no live rock, I added a handful of live sand and 2 pieces of good live rock. I used all 100% RO/DI water. The only thing really contributing iron to the water column would have to be the GFO. I mean there is no other source of it that I would possibly no of. No additives, I guess it could be food but the tank has only been running for 3 weeks I don't think it could accumulate enough iron from the food.

 

[Reefsi]

Im not that concerned about it, Its not like an absurd amount. I just wish I could prevent this from happening every time I add GFO.

 

[HighlandReefer]

Well, if the GFO is causing your problem like it sounds to you, it's cheap to give the filter bag a try. I'm not saying that GFO is not causing your problem. You could switch to an aluminum phosphate remover if you like. I would use a filter bag after the aluminum based phosphate removers due to possible concerns about aluminum in a reef tank. Randy has a good article regarding the use of the aluminum phosphate removers which would provide more insight.

 

[trinidiver]

But if its a new tank that is only on week 3 and still going through the stages of cycling, why are you cleaning and stirring up your sandbed?

 

[Reefsi]

Thanks for the information, it is well appreciated. Yeah I think I'm going to try to hang the filter sock above the water verses it hanging in the water.

 

[HighlandReefer]

Your welcome. :thumbsup:

 

[HighlandReefer]

But if its a new tank that is only on week 3 and still going through the stages of cycling, why are you cleaning and stirring up your sandbed?

With a shallow sand bed, your not going to get much nitrate & phosphate reduction like perhaps a deep sand bed. Therefore, you want to rid the shallow sand bed of all fecal material, extra food, organic debris and other sources of nitrate & phosphate routinely (perhaps weekly). If you let the debris build up for too long, then when you clean the sand bed it will release a lot of nitrate & phosphate into your water column.

 

[trinidiver]

I understand what you are saying, but what fecal material, extra food, organic debris would he have in a tank during week 1-3 of a cycle. He also had no live rock and live sand.......... correct me if I am wrong

 

[Reefsi]

My only confusion is this, I understand why algae grows and what it uses to grow. I have non of that, zippo, zilch, natta, none. No excess nutrients whatsoever. So can the cyano purely grow off of iron?

 

[bertoni]

Every living thing requires a lot of carbon, nitrogen, and phosphorus to grow. Photosynthetic organisms can get carbon from the atmosphere, but the other two are coming most likely from food, in this case. Some organisms can fix nitrogen from the air, but that's likely not happening to any significant extend in your tank.

 

[Randy Holmes-Farley]

Live rock itself can provide a lot of nutrients when moved from one tank to another, which kills many organisms.

 

[tmz]

There are lot's of reasons cyano forms in a aquariums particvularly new ones until things settle in.
BTW, the bacteria that you hope to establish in cycling need phosphorus, nitrogen and organic carbon too.


New live rock is likely a significant contributor of nutrients as Randy noted.

It's also possible , the extra gfo knocked the PO4 and silicate down far enough that some of cyano's competitors are limited giving it an edge.

Cyano is pretty effective at scavenging iron as Randy explains in his second article on iron; but no , it can't live off iron alone ;it needs phosphorous but is likely getting that from organic matter or scavenging it from the water ; much of it can make it's own bound nitrogen and organic carbon but it also benefits when these are readily available.