Lyngbya (I think) help

[hardmermaid]

Hi,

I believe I have a lyngbya problem starting and am seeking guidance and opinions.. I don't think it is GHA because I syphoned some about a week ago and it's still present in the can I syphoned it into and it hasn't been getting any light. I've also have low nutrients. There is also a small bryopsis outbreak (few patches and spreading) but I will deal with that later. I think this is different.

info:
Tank: 100gal of water. 10months old. 90% dry rock and 10% TBS live rock.
Nitrates: 3.5. Dosing Neonitro 5ml a day to maintain this or it will go to 0.
Phosphates had been steady at 0.08 for months but recently went to 0 when this started.
Dosing 5ml microbacter7 weekly
Calcium: 450
Alk 8.4
mag 1400
salinity 0.0125
Livestock: 8 anthias, 4 chromis, several turbos/other snails/hermits/2 conches (I don't think it is a CUC issue)

It is mostly one the end of my peninsula tank. I have greatly increased the flow on that end and it has not been coming back on the sand. It is spreading on rock though. I am about to go out of town for 2 weeks on Tuesday. I will do a 15 gal water change to siphon out what I can but it doesn't easily come off the rock. I have someone coming over once a day while I am out of town. I am wondering what I should have them dose.

My questions:
Does this look like lyngbya to you?
Should I dose to maintain nitrates 3.5 and phosphate 0.03-0.05? They will go to zero without dosing at this time.
Should I continue to dose microbacter 7?

There is plenty more :(

Thank you for the assistance!

 

[EnterName]

A microscope would make the identification easier. 200-400x magnification should be enough, and you don't need an expensive scope at all.

Lyngbya tends to be less green and more brown in reef tanks, so there's a good chance you just have GHA. But color is a bad indicator, because cyanos can change color based on the environment.

I would stop dosing nutrients for now. Our tanks have nutrient levels orders of magnitude higher than the ocean. All the organisms we want to keep are well equipped to deal with levels below the detection limit of hobby-grade test kits, and the growth proves there is enough nitrogen and phosphorus available.

I would also stop dosing bottled bacteria for now. Many of these products are just nutrient bombs themselves, and we don't know how many of the contained bacteria manage to wake up from their cyst state and then attach to surfaces instead of ending up in the skimmer. If I remember correctly (don't quote me on that), the bacteria that actually establish long-term in reef tanks don't have cyst states or can't be cultured well, meaning they cannot be bottled. So even if there was an effect, it could be short-lived, and the cyanos appreciate the nutrients they get.

Unfortunately nutrient control is often insufficient for algae/bacteria control, because there is no set of parameters that allows coral growth but not algae/bacteria growth. Manual removal and appropriate CUC members will be an important part of the solution, but for Lyngbya this becomes more difficult. I'm not sure what actually eats it.

I would perform large water changes to get rid of dissolved organics. We don't know much about them yet, but people have theorized for a very long time that they might play a role in cyano blooms. That kind of makes sense if you think about how carbon dosing can boost bacteria growth. If nothing helps you will need to properly identify it and then use an appropriate antibiotic or fluconazole if its GHA.