Is this hair algae?

[hvacman250]

If not, what is it? Might be hard to tell by the picture, but it's brownish-yellow, almost caramel colored. Hairy, but fluffy, too.

As you can tell, is only in one spot of the tank. VERY hard to remove. A toothbrush wont budge it; it takes a courser bristled brush, and even then its hard to remove.

Why in only one spot of the tank???

Edit: Tank is 2 months old. Parameters in sig.
I do a 15 gallon water change every Saturday with RODI/Aqua Vitro salt mix.
Feed daily, but lightly with Rods food. Food is gone/eaten within 5 seconds. I'd guess a tablespoon of food lasts about a week-10 days.
1 lb of carbon in sump gets changed every 2 weeks. Bag of white PO4 pellets from LFS gets changed every 2 weeks.
Chaeto in refugium. Has doubled size in 2 months.
Have a Octopus skimmer rated at 180 gallons. Skimmer isnt pulling tons of crap out, but I only have about 7" of fish.

 

[quickwiz00]

Yep, I'd say it does appear to be some nasty hair algae. All new tanks go through different algae battles. Looks like it's the hair algae's turn.

Your parameters appear fine to me. Maybe try increasing your water changes (with RODI) and minimize your feeding for a while. You could also add some carbon for export of nutrients.

If you have a skimmer, maybe try skimming a little wetter.

On a side note, a sea hare will take care of it, but that doesn't address the initial cause. Also, I am not sure, but a sea hare may need a more established tank. Additionally, sea hares have a very strict diet and will die once the algae is all eaten.

 

[hvacman250]

Yep, I'd say it does appear to be some nasty hair algae. All new tanks go through different algae battles. Looks like it's the hair algae's turn.

Your parameters appear fine to me. Maybe try increasing your water changes (with RODI) and minimize your feeding for a while. You could also add some carbon for export of nutrients.

If you have a skimmer, maybe try skimming a little wetter.

On a side note, a sea hare will take care of it, but that doesn't address the initial cause. Also, I am not sure, but a sea hare may need a more established tank. Additionally, sea hares have a very strict diet and will die once the algae is all eaten.

I'm perfectly content to wait it out. I was expecting some initial, new tank algae blooms, but why only one part of the tank.
I will add this to the original post:

I do a 15 gallon water every Saturday with RODI/Aqua Vitro salt mix.
Feed daily, but lightly with Rods food. Food is gone/eaten within 5 seconds. I'd guess a tablespoon of food lasts about a week-10 days.
1 lb of carbon in sump gets changed every 2 weeks. Bag of white PO4 pellets from LFS gets changed every 2 weeks.
Chaeto in refugium. Has doubled size in 2 months.
Have a Octopus skimmer rated at 180 gallons. Skimmer isnt pulling tons of crap out, but I only have about 7" of fish.

 

[bazineta]

Often the locality is due to detritus collecting in a spot with low flow. Alternately, it might be a place your fish have chosen as their, shall we say, thoughtful spot.

 

[hvacman250]

Often the locality is due to detritus collecting in a spot with low flow. Alternately, it might be a place your fish have chosen as their, shall we say, thoughtful spot.

Never would have thought of that. I dont think its the case though.

18" away, pointed directly at it, is a Koralia 4 and an MP40ES.

This 100 gallon tank has about 7000 GPH of flow.

Now that I think about it: The same place the hair algae is now is the SAME AND ONLY place I got a diatom bloom.

 

[quickwiz00]

Never would have thought of that. I dont think its the case though.

18" away, pointed directly at it, is a Koralia 4 and an MP40ES.

This 100 gallon tank has about 7000 GPH of flow.

Now that I think about it: The same place the hair algae is now is the SAME AND ONLY place I got a diatom bloom.

It sounds and appears that you have a very well maintained tank. The only things I could suggest would be a 3 days lights out, wetter skimming, and a temporary decrease in feeding. This in combination with your good husbandry (and maybe some GFO if all else fails) should produce positive results.

Just a thought, but if it appears to have stagnant and isolated growth confined to those one or two rocks, maybe that particular rock is saturated with nutrients ie phosphates; this in turn can cause the algae to only grow on it. Again, not very sure about the last statement, just a thought.