Cyano that grows in the dark?

[Rhodesholar]

Hello everyone.

I have got the weirdest problem going on here.

I have what has got be Cyano growing on my sand but it gets worse overnight.

When my lights come on it like burns off of something. Next morning it's back.

I don't even know how I have this issue as my tank parameters are great.

PO4 0.01
Nitrate 0
Alk 9
PH 8.3

and I have tons of flow. I am running (2) 4100 gph power heads and 900gph return from my sump.

I can't figure this out.

Anyone have any ideas? Like I said it's worse after the tank has been dark all night. I thought Cyano liked light not the darkness.

Thanks to anyone who responds.

[Michael Hoaster]

Well there are different kinds of cyano. Maybe there is a dark-loving variety? Can you post some pics showing the difference between morning and late day?

[miralami]

Cyano isn’t an Algae to react to light it’s bacteria.
You’re parameters are not perfect, you can’t have any life in your tank with zero Nitrate and Phosphate.
Increase your feeding and syphon those out, you will see the improvement slowly.


Sent from my iPhone using Tapatalk

[Rhodesholar]

Hanna ULR = 0.01 phosphate
API Nitrate test kit = completely yellow (no nitrate or not very high)

I am sure there is some Nitrate but it is very low.

Can I have PO4 or Nitrate bound up in the sand?

I have (1) SPS coral frag. Great polyp extension and growing.

I just have this red stuff all over my sand. Just the sand. No where else.

And how can you say my water parameters are not perfect? Everything out here I have read says Nitrate and Phosphate should be undetectable. They pretty much are.

PH 8.2 to 8.4. per my calibrated Milwaukee MC122 PH monitor/controller.

You can't maintain that high of PH level and have major problems no?

The only thing I can think of is that I have organics bound up in the sand. Not sure how that is possible when I have tons of flow. Can it be the sand? Like just some kind of crappy sand?

I have 100lbs of live rock and it's clean as a whistle. Just the sand is the issue.

So not sure where my water parameters are out of whack

[jjencek]

Originally Posted by Rhodesholar

Hello everyone.

I have what has got be Cyano growing on my sand but it gets worse overnight.

I was wondering about the same thing. I got the same in my tank. Bad in the morning and gets better during the day. I plan to stick under microscope and see if I can ID it.

[Rhodesholar]

Jjencek,

That would be really cool if you can ID it as it sounds like were both dealing with the same thing.

In previous tanks I have had Cyano breakouts but they usually happened if the sand was seriously disturbed such as a power head coming loose and blowing it around.

Also for the record I don't have a DSB in the display. I do have one in the fuge and I have always kept one in my fuge and never had any issues people have claimed about DSBs. Also my DSB in the fuge is perfectly fine. It's just the display.

I don't know if this has anything to do with it and perhaps I am seriously reaching but I do have moonlight LEDs. I don't know but would that be enough light? I wouldn't think so but who knows.

It's definitely worse in morning and improves the longer the main lights are on.

[Vinny Kreyling]

According to my chemist friend in the hobby -0- is not something we should embrace.
Nitrate & Phosphates are used by all living creatures in the water. He recommends Nitrates up to 10 for a reef. Phosphates are another quandary. The 20,000 gallon reef tank on LI runs around 0.16, everything looks great & grows very well across all the corals.

[Timfish]

I guess it could be some kind of cyano that prefers low light. (Keep in mind moonlight shold be about 4000K and only ~.3 lux or ~.006 PAR, most "moonlights are much brighter and blue so photosynthesis may be occuring.) Is it possible during the day it's getting disturbed by fish and invertabrates? Maybe flushed up into the water column and settling at night?

I would agree with Mirilami your water parameters are not ideal. A couple decades ago assumptions were made about nutrients science has since shown to be incorrect. I would encourage you to get Forest ROhwer's "Coral Reefs in the Microbial Seas" It expalins how labile DOC influences autotrophic and heterotrophic bacteria to the benefit or detriment of corals.

SPecificly addressing PO4 levels researchers at Southhampton University have shown PO4 levels below .03mg/l can create a phosphate deficiency in corals that will promote bleaching and death. Here's links if you're interrested in readuing further:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching (bad N:P ratio):
http://www.indiaenvironmentportal.or...enrichment.pdf

Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:
https://www.frontiersin.org/articles...015.00103/full

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://www.sciencedirect.com/scienc...601?via%3Dihub

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach (increasing P04 increases coral growth)
https://www.sciencedirect.com/scienc...22098111004588

High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
http://jeb.biologists.org/content/214/16/2749.full

A point about Nitrates; Corals have diazotrophs in their holobiont that are converting nitrogen gas dissolve in the water (N2) into nitrates for the corals use. Corals also preffer ammonium from fish to nitrates, nitrates can actually be bad for fish. Here's a couple links:

Diazotrophs fix N2 for corals
https://pubmed.ncbi.nlm.nih.gov/27335448/

Context dependent effects of nutrient loading on COral-Algae mutualism
https://esajournals.onlinelibrary.wi...1890/13-1407.1
Here's fig. 3 from this paper

[Rhodesholar]

Timfish,

I don't have any sand stirrers so it is not get moved around.

I think we hit on something. I am going to leave the moonlights off and see if that doesn't make a difference. If that does make a difference then I will get some kind of filter over them to cut the brightness because they are pretty bright.

On to water parameters.

I am sure I have more PO4 then my Hanna checker is stating same as Nitrates.

I feed my fish regularly both flake and frozen so that alone has to be putting in PO4 and Nitrates no?

Also I have a DSB in my fuge and I change water maybe once a month or so. So I don't think my water is ultra clean to the point it would be detrimental. I have one SPS coral frag and it has good polyp extension, good color and is actively growing.

I do run GFO but at half the recommended rate and it's changed out maybe once a month or so.

But to take into consideration what you have said I think I will procure a more accurate Nitrate test kit just to make sure. However if my Nitrates are actually undetectable then that DSB has to be doing a good job.

I am going to do another PO4 test here in a few minutes and see where things are at.

[Rhodesholar]

Everything I have read says that Po4 in a reef tank should be unmeasurable.

[Vinny Kreyling]

Well, @ some time the world was thought to be flat too.
Things change as we learn more.

[Michael Hoaster]

It's the symbiotic algae within the coral that needs a tiny bit of phosphate.

[Sk8r]

My sig line has parameters that work pretty well for stability.