I beat hair algae

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Well, a little premature as I still have some in the tank, but I'm definitely heading in the right direction.

I thought I'd touch on what I did to the tank and how the tank naturally progressed.

The tank (Red Sea 425XL) was new last November (2021) with new Marco rock and new sand. But, I put 50 - 60 kgs of super mature rock from my previous tank. I reckon some of it might have been 15+ years old. This is my first new tank, rock, sand in that same 15 year period. Dry rock was unheard of back then. I think I underestimated what it would take to seed and mature this rock and in hindsight I moved things very quickly. I'm also used to a tank/system with twice the volume.

I've never been shy of phosphates. I've had good results with higher phosphates in some previous tanks so I'm not (usually) one to jump up and down when phosphates go above .1, .2, .3 etc. But this new tank hit about .8 in June / July ish. It was at this stage I noticed the hair algae. Fairly small at first but will eventually be 1"+ in length on every rock and back glass surface of the tank.

I have a little bit of 'old-reefer syndrome'. I missed a lot of things during this because its been so long since I've had any issues with anything.

The following took place, not in this order, over the following 4 - 5 moths or so, to now.

BTW - I *definitely* looked for a silver bullet. There just had to be a simple solution to just dose into the tank and all is well..... Yeah right.

  • I started running lots of GFO to get phosphates down. This worked for the phosphates but played no part in eradicating the algae. Note that for some reason I was ok with them being in the .1 - .2 region. It was a long time (literally till 2 weeks ago) before I used lanthanum for a much finer grained control and reduced them to ~0.02 - 0.05. I dose this daily at the moment.
  • I ran a course of Dr Tim's 'Getting rid of Algae and Cyanobacteria' (https://www.drtimsaquatics.com/wp-content/uploads/2020/11/Cyano_Algae_prescription_recipe.pdf) this was great, but just not for anything other than tank sludge.
  • I introduced *lots* of new bacteria. (part of my silver bullet thinking)
  • I used peroxide, liberally, inside the tank to melt the algae. It would go away from that spot on the rock but be back in a week or so. I did this for weeks. I believe it was the reason I lost 2 cleaner shrimp.
  • I bought 2 pigmy sea hares. They looked cool for a few weeks and I never saw them again.
  • I kind of realised how pissy my clean up crew was compared to the old tank. I had almost no turbo snails at all because they hadn't had time to reproduce and I'd not noticed. I did have a few hermits and trochus snails but these didn't do much. I now have a lot of very large turbos and every night I can see the baby turbos all over any algae in the tank.
  • I had very few *good* algae eating fish. My 16+ year old purple tang hasn't pecked at rocks in years! I will eventually add 2 x lawnmowers, 1 x two bar rabbit, 1 x fox face and a mimic tang. I don't plan to keep them for a long time and my LFS has some big empty tanks for me to take them in. These guys are all pecking at the rocks now which is a good sign.
  • I totally underestimated how much manual removal would help. It makes perfect sense, you remove it and there's more food for other life (chaeto, bacteria, etc) and it also wont be returned to nutrients if it dies or is eaten. I don't know why I discounted this. But I'm now manually removing at least every 2 days. The amounts are getting smaller. BTW I also used a toothbrush to scrub rocks in the tank. I do not recommend this when you're in the early days because the conditions are just so good that whatever you scrub off will likely land and grow somewhere which sucks. BUT I'm now using a tooth brush again in the later stages of this battle (once you start noticing the algae not coming back as quickly) and I don't find that its causing any issue at all to scrub it off. Some of it just cant be grabbed anyway.
  • I reduced my skimmer. Its now far more dry and in connection with turning off my UV (which seems counter productive) I believe I am significantly boosting bacteria numbers.
  • I started feeding LOTS of phyto. I'm at around 150mls per day at the moment. I'm keeping pods fed as well as corals and clams and the phyto also consumes nutrients before they are consumed themselves. This amount does zero to my nitrates and phosphates.
  • I started dosing nitrate. YES! You read that right. My phosphate had been above .1 and nitrate around 1.5. After a lot of reading it made sense that the things I wanted to thrive needed more nitrate in the nitrate:phosphate ratio they consumed. This was a big thing and the single most noticed difference with the algae. When I got that nitrate up around 5 - 6, which required daily dosing despite heavy feeding, I could see (and feel) the hair algae growing slower and coming out easier.
Its still very dark and theres still a lot of it. I believe I have 2 species of it in the tank as they definitely feel and grow differently. I don't think I have briopsis because mine doesn't have a fern-like structure to it.

The tank is now around 13 - 14 months old which means I've hit that golden '12 month' maturity which will be helping with the problems also.

Once we're on the other side of this, my tank will need a baby reset. My nutrient addition will need a lot of focus along with nutrient removal. Once I'm not feeding all that algae theres obviously going to be a little bit of a settle period. Hopefully I can maintain good phosphate and nitrate numbers with just my big chaeto fuge. Also I know that a lot of the baby snails are likely to not survive when all the food is gone, so we'll need to reach a bit of an equilibream with the clean up crew and the amount of food.

Anyway, I'm hoping that people who are really fed up with hair algae can have a read. As I said theres no silver bullet but theres some steps you can take to try and help things. I never thought about throwing in the towel. Wheres the fun in that?



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I use fluconazole. Takes 10 days.

Sometimes requires a second dose but usually does the trick.
Yeah I thought about this but didn't due to several reports I read about the non gha life it might affect. From bacterias and macro algae to corals and inverts.


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Yeah I thought about this but didn't due to several reports I read about the non gha life it might affect. From bacterias and macro algae to corals and inverts.
I use it often enough in systems with all sorts of sensitive pieces. No problem.

Only problem comes when all the gha (or bubble algae at 4X dose) melts and releases nutrients back in the system. Avoidable if you're good about WC