GHA gone. Should I be worried...

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This isn't a new tank going through "the uglies." Well, maybe super slow uglies ...

I've had this tank for about 2.5 years. Red Sea Max Nano 26g. It's been a source of joy and many unplanned "science fair projects" and has taught me patience and failure. One constant however, once the diatom phase finished, has been green hair algae. I aided the chaos intentionally and unintentionally. Intentionally, I let gha grow because I raised 20 little lettuce nudibranches (pic below) - so fascinating and fun! Unintentionally, because I added fish guards to both my overflow and VorTech mp10, which significantly impeded flow.

In case you think I'm overstating how ugly things got, I've attached a pic, about a year ago. Yes, I cleaned this out every 1-2 weeks.

TLDR: my gha has completely cleared/balanced over the last month (see video), largely due to improving flow and a few excellent CUC, I think. Do I dare think I'm in a good place finally - or is this just a harbinger of some fresh doom around the corner?

Other possibly relevant info:
My microbiome and substrate are awesome. From day 1, I've added regular copepods and occasional PNS Yello Sno and Probio from Algae Barn. I have all kinds of good, microscopic things crawling around. And gha, mostly derbesia (many samples under microscope).

I've never added chemicals to the tank, despite wanting to on occasion. Corals that weren't on the main rock, I did remove and occasionally treat their small rocks with hydrogen peroxide. That was great for some, for a short period only, and awful for my mushrooms and blasto (the latter is growing back). My corals have grown and really started to take off about a year go. I always reasoned that if I am able to grow that much gha, my tank is really good at sustaining life, so I should look to fix whatever is the root cause and not treat symptoms. So, I personally grew patience.

I've always had CUC, but it's been hit or miss. Ceriths breed readily in my tank. I have a beloved pincushion urchin and tuxedo urchin who are solid workers, although they limit my coralline, too. I also have about 5 nassarius snails who work the night shift, and a bunch of bumblebees (I swear the bees are breeding too, because there are more than the three I had originally). Trochus, astrea, and Mexican turbos have been a sad story. They live about two weeks, much to the delight of the "beehive." However, a helpful poster here pointed out we keep our tanks warmer than some of these snails prefer, and suggested zebra turbos were the best - BINGO! I started adding zebra turbos a few months ago, after tank cleanings, and that's definitely been a difference maker. I have 5-6. I also added a small conch a month ago, and it's been great on the substrate.

I have one fish, an adorable Molly Miller Blenny from Biota. I did have a little bubble algae and occasional aiptasia, but not since my little fish grew up! I know I'm only adding to anecdotal evidence, but I know my fish keeps those nuisances away. I only have the one little guy because I grew the reef first. I know that's backwards from most, but I wanted to establish the substrate and corals first, slowly. It's a hobby, not a race, right? If I were a fish, I don't think a stark tank full of fluctuating parameters would be super fun. I haven't added any more fish because I'll be upgrading to a 100 gallon next year and I don't really feel like chasing down more fish in the tank transition. That little Blenny is wicked fast!

The corals are a mix of soft (that's red xenia on top), mostly lps and a few sps. All with stories of their own.

I removed the extra guards on my mp10 and overflow about a month ago, mostly because I was tired of cleaning them, and the flow dramatically improved.

I change about 15% water with NSW every 1-2 weeks. I never saw a spike in any parameters at any time. I used to check constantly and now just monthly. Parameters a week ago, when the last of gha gave up, all Hanna:
Alk 8.1
Cal 450
Mag 1295
Nitrate 1.4
Phosphate 0.07
I keep pH around 8.1

I run the stock protein skimmer and stock light, mostly blue. I dose 4.5ml of All For Reef in the morning.

So, is this a tale of time, patience, the right CUC, and good flow finally? Or, should I be worried and testing for something else. There is still some gha growing and definitely coralline. I might need to supplement my cuc, though?

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Lelegance

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Just means your coral are outcompeting and the tank is maturing. No bad signs that loosing gha would show, especially if coral are still happy.
 

EnterName

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First of all:
It's absolutely great that you didn't let yourself get discouraged by this algae issue.

Regarding your concerns about the future of your tank:
Now that the green hair algae is gone something else will be trying to get the available nutrients, so you might want to watch nitrate and phosphate a little bit closer for some time. In a best case scenario your corals will gladly consume the now freely available nutrients and everything will be fine. I still would invest in an ICP-MS test to verify everything is as it should be, especially considering that green hair algae likes to drain certain trace elements quite fast.
 
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tbox

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Just means your coral are outcompeting and the tank is maturing. No bad signs that loosing gha would show, especially if coral are still happy.
Thanks! Corals seem to be very happy, although my red xenia hasn't fully adjusted to the flow changes. The rest are delighted.
 
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First of all:
It's absolutely great that you didn't let yourself get discouraged by this algae issue.

Regarding your concerns about the future of your tank:
Now that the green hair algae is gone something else will be trying to get the available nutrients, so you might want to watch nitrate and phosphate a little bit closer for some time. In a best case scenario your corals will gladly consume the now freely available nutrients and everything will be fine. I still would invest in an ICP-MS test to verify everything is as it should be, especially considering that green hair algae likes to drain certain trace elements quite fast.
Thanks for the great advice. Sunday is wc day and I'll test everything again.

The algae was a slog and certainly tested my patience. But I absolutely love how healthy everything is looking, and knowing how nicely established my tank is now. Fingers crossed.
 

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