Is there anything else cyano likes?

Nitrates 0
Phosphates 0
New Bulbs
Good flow
New power ehad in sump with my chaeto
Use RO DI water
Running chemi pure elite and GFO
I do about 3 water changes per month

Why do I still keep getting annoying patches of cyano, especially in my sump\fuge? It grows on top of my chaeto.
I know, you might say that the slime is eating the nitrates\phosphates before the test can get them. But then why when I clean the slime out of everywhere I see it, and then test the water over the next few days, my tests still come out good? But then a week later the cyano starts forming again.
Are some strains just that hard to get rid of? Should I use red slime remover? It's not like it's epidemic, you really have to look at it to notice it, but it's annoying for me, and I can immagine that if I let maintenance slip up, this stuff would take over rapidly.

 

I guess I would look at the RODI water and test for TDS, and re-examine feeding regime.

 

TDS 0, water from the RO tests fine. I've been feeding twice a week, 1 cube of either mysis or cyclopseez.

 

Does the tank get any natural sun light?

Consider a ATS if you have not. Sounds like you have researched and intervened in all the right areas. I do not think it's any one thing but the sum of things.

Any slime remover products will just be a quick fix, it will come back.

Good Luck

 

Part of the problem is that your test kits aren't measuring the right forms of nitrogen and phosphorus. Cyanobacteria fix nitrogen from the air so not have any nitrogen in the water in the form of nitrate is of little concern to them. They are on top of your chaeto because that probably gives them maximum exposure to the air (i.e., nitrogen).

As for phosphorus - your kit only measures inorganic phosphate (PO4 3-) also called orthophosphate or soluble reactive phosphate (SRP) but the vast majority of phosphorus in seawater (and an aquarium) is in the organic form. The organic form can be degraded by bacteria producing SRP but then this SRP is quickly utilized by the cyanobacteria.

The only way to get 'control' is to use something to out compete the cyano - how often do you harvest the cheato?

 

I was just about to mention phosphates. The reading of 0 is because phosphates are being used up by the cyano bacteria which you are seeing in your tank. I would recommend manually removal of cyano if possible - if not that, then try using a toothbrush on the rocks and removing clumps of sand where the cyano is sticking to.

+1 to using cheato - if you don't do this already...should help with keeping down levels of phosphates a bit as well as nitrates. You should trim the cheato every once in a while - this is when you are actually "exporting" the nutrients.

 

No Natural sun light.

I've brought water samples to my local reef store to double check, and they said my water is perfect.
I was harvesting chaeto every couple of weeks, my sump was full. It's dwindled down to a small peice, and now I only rip off peices that the slime is growing over. But the chaeto is considerably smaller and doesnt grow noticibly anymore.

I remove all cyano that I can during every water change. Which is why I'm baffeled about it outcompeting my chaeto.

Like I said, it's not like I have cyano all over the place, I have a few very small patches on my rocks, but in the sump is where it's annoying, especially outcompeting my chaeto.
I do have a bunch of live rock in the sump, maybe I should take out. Could be where detrius collects? I just want to kill this cyano off, which is why I was wondering if the red slime remover products would help.

 

First, the test kit reading of 0 doesn't mean anything as no hobby test kits are particularly accurate at such low levels.

Cheato may be effective, but it seems to me cyano is very adaptive and focusing on just one area of attack is prone to lead to frustration.


Note: for those not interested in technical info, skip to the list at the bottom for suggestions, but I'm interested in Dr. Tim's thoughts on some topics as he's a great resource to have on the board

So, as mentioned test kits are not going to provide accurate reading at levels which would be expected to limit cyano. Regardless, for the most part, as you alluded to, organic PO4 isn't directly usable by most algae (there are some dinofalagellates for example that can do so, but this doesn't seem to be particularly common).

Cyano may or may not; of course, it's generally considered to be photoautotrophic, although certainly, at least a few species have been documented to have heterotrophic modes. I do believe that some cyano may consume organic nutrient sources in our systems though, although, this is speculation really.


Even if the cyanobacteria aren't consuming it directly, the cyano may be utilizing it through mutualism with various heterotropic bacteria coexisting in the mats of cyano we find in our systems. So, it seems there is a possibility that cyano may directly, or indirectly utilize inorganic PO4 to some extent.

Cheato is photoautotrophic so, it is not going to touch organic phosphate. It will only consume it once it has broken down into inorganic PO4. Same with GFO, or aluminum oxide binders etc... (not that they are photoautotrophic, but that they bind inorganic phosphate).

So, if we assume cyano in our system, truly functions autotrophically, and not heterotrophically, then they are on par; if we don't assume this, then cyano would seem to have a competitive advantage as it doesn't need to wait for the inorganic products. If on par, then it just depends which can filter the inorganic phospourous from the water first. This seems to be cheato, possibly due to the larger surface area? I'm not sure of the reason really, but would be interested if you have any ideas? So, then all things being equal, cheato may out compete cyano, except, as you mentioned, cyano can fix N2. So, if the nitrogen supply becomes diffusion limited, then cyano still should have the advantage.

However, Cyano appears to be a common byproduct of carbon dosing. Although, again speculation, this would seem suggest that either cyano is utilizing organic phosphourous, in our systems, or there is a diffusion limited supply of N, as N is typically depleted before P when carbon dosing. Either way would provide cyano with some advantage.

Also, cyano has an advantage over cheato with regards to other nutrients, such as iron, as it utilizes siderophores, whereas cheato, as far as I'm aware, does not.

It's not uncommon for people to see cheato gets over-run with cyano. Possibly this has to do with access to air, however, IME, dosing iron and/or KNO3 usually helps in this situation. So, diffusion limited availability of iron and NO3 may be occur in some systems. Possibly the cyano is even utilizing organic sources (either directly, or via nutrient cycling with bacteria) from the decaying cheato after out competing it for other resources.

I agree though, if there is not a diffusion limited supply of iron and NO3 (or possibly excess organic phosphourous) then cheato does seem out compete cyano. If there is, then dosing these should help. However, binders such as GFO will also help and anything to remove organic forms, such as carbon or help convert them to inorganic forms such as a CUC or bacteria can help.

So, my standard routine for cyano is along the lines of:

1) Run GFO change out often.
2) 15% per week water changes (or more) using 0TDS RO/DI water.
3) Run lots of carbon and change out weekly.
4) Remove detritus from system - sand, rock, filters, sump etc...
5) keep filter material clean
6) Wet skim to make sure organics are removed from water column before breaking down.
7) Don't overfeed and many feeding are better than one, to make sure all food is consumed.
8) siphon out existing cyano, or increase flow to get into water column for removal by skimming. Siphoning is probably more effective though.
9) make sure you have a sufficient CUC to remove any waste.
10) cheato although possibly will need to dose iron (maybe KNO3 with caution).
11) cut back on carbon dosing if doing so, and none of the above are working.
12) Possibly adding a bacterial supplement to compete with the cyano, although there are a lot of unknown variables with this route, so I tend to be skeptical; although some do report succes.

I'm not a huge fan of chemi-clean and lights out approaches, as they don't fix the underlying issue. Also, they release lots of waste into the system quickly as the cyano dies off and, may directly or indirectly stress other organisms. Chemi-clean also is reported to occasionally crash biological filtration, although not often.

 

I've been doing a lot more research and it's brought up a bunch of threads about people switching away from reef crystals, and the cyano going away.
I use reef crystals. Has anyone had this experience?

 

I can't say I've had the same experience as I've never used reef crystals. However, if you suspect your salt mix, I'd suggest testing a fresh batch before using it. If you do get 0 readings but don't trust the results, then switch anyway.

What's interesting to note is that the tanks at my LFS are always squeaky-clean, despite the fact that there is no sand or rock in any of their tanks which are usually overstocked, as well. Although they sell IO products, they will only use Red Sea in their own systems.

Just something to consider...