Problem solving algae in a mature, low nutrient tank

[Spencer7]

I would say it looks like Brown Hair Algae, let me know what you think.

Tank facts...
- RS 170, ULNS w/one Talbot's Damsel, SPS dominated
- Eight months old in this location but ~2.5 years running (transition to new apartment was smooth)
- NO3 tests at 5-10 ppm (Nyos kit)
- PO4 tests at 0.00 ppm (Hannah)
- Coral Box D300+ Skimmer (on 24/7, have also played around with running it at night only and with not running one at all)
- Mitras/T5 lighting (bulbs recently changed)
- 2x MP10s (85% reef crest)

Context:
- I feed the damsel 1-2 times a day (PE flakes) and feed the coral once a day (e.g. Coral AB+, EasySPS gel, Vitalizer)
- I have biological media in the sump with a lot of mature surface area and sponges
- RODI water (clean filters)
- 15% water changes every 7-10 days (ReefCrystals)

This brown hair algae has become more of a pest over the past 4-6 months. It hasn't changed based on which coral food I try.

I dose about 1.2mL of NeoPhos a day. I stopped dosing NeoNitro a few weeks ago to see if it would help. I was using both NeoNitro and NeoPhos previously, before hair algae became a thing. I started dosing the Brightwell products due to my low bioload, and low nutrient issues (pale corals, little cyano when phosphates hit zero).

I plan to add a fish or two and stop dosing NeoPhos as well. I just need to be careful about having food for the coral.

The algae isn't the end of the world but I think it does irritate some of the coral (and obviously doesn't look great). It makes me perform water changes more frequently to enjoy the tank (and my nutrients are low as is).

 

[kharmaguru]

I don't see any snails. Is there a cuc?

 

[griss]

I don't see any snails. Is there a cuc?

Agree with my neighbor to the north. Do you have any snails or hermits?

 

[Spencer7]

I only have a few - maybe two trochus and two Astraea Turbo Snails. Could get some more inverts.

It doesn't look like it but the algae is growing in the highest flow area, so the snails are crazy about grazing there. Also, the rock work is a bonsai tree of branches (precarious to climb).

I had a pygmy angel who jumped from the tank...I think I'll get another grazing fish (e.g. lawnmower blenny) because of how much of a rockstar that guy was. I have a net cover for the RS170 I can assemble.

 

[kharmaguru]

I only have a few - maybe two trochus and two Astraea Turbo Snails. Could get some more inverts.

It doesn't look like it but the algae is growing in the highest flow area, so the snails are crazy about grazing there. Also, the rock work is a bonsai tree of branches (precarious to climb).

I had a pygmy angel who jumped from the tank...I think I'll get another grazing fish (e.g. lawnmower blenny) because of how much of a rockstar that guy was. I have a net cover for the RS170 I can assemble.

Do the trochus or astraea graze on it at all? It might not be super tasty and you could try some different snails. I find ceriths will eat some pretty horrendous stuff but they're not too fast so I'd get at least 6. They'd have no problems climbing all over that. Adding some live pods could help too. The fact you have a monoculture of pest algae is a bit troubling. It could mean you are fairly imbalanced biome-wise and you could use a new piece of mature live rock from somewhere you trust to introduce some micro competition. You do have some lovely coralline growing though.

 

[Genetics]

I’m with the people above. Try a different snail species. Mexican turbo snails should enjoy brown algae. If you have a sandbed try nassarius snails to get and detritus.

I would argue that brown algae would suggest more than enough nutrients in the water for corals.

 

[BeanAnimal]

I would significantly slow down the feeding for a few weeks. I don't think the fish or coral will suffer. The nutrient levels in the water tests may be low, but that may because your are fertilizing the algae and it is sucking it up pretty quickly.

Get some grazers as well. Turbors, ceriths and astreas are all good.
Manual removal is also going to help. You just have to keep at it and get ahead of it along with the other measures.

 

[JohnL]

How is the situation now?

 

[369Augold]

I would say it looks like Brown Hair Algae, let me know what you think.

Tank facts...
- RS 170, ULNS w/one Talbot's Damsel, SPS dominated
- Eight months old in this location but ~2.5 years running (transition to new apartment was smooth)
- NO3 tests at 5-10 ppm (Nyos kit)
- PO4 tests at 0.00 ppm (Hannah)
- Coral Box D300+ Skimmer (on 24/7, have also played around with running it at night only and with not running one at all)
- Mitras/T5 lighting (bulbs recently changed)
- 2x MP10s (85% reef crest)

Context:
- I feed the damsel 1-2 times a day (PE flakes) and feed the coral once a day (e.g. Coral AB+, EasySPS gel, Vitalizer)
- I have biological media in the sump with a lot of mature surface area and sponges
- RODI water (clean filters)
- 15% water changes every 7-10 days (ReefCrystals)

This brown hair algae has become more of a pest over the past 4-6 months. It hasn't changed based on which coral food I try.

I dose about 1.2mL of NeoPhos a day. I stopped dosing NeoNitro a few weeks ago to see if it would help. I was using both NeoNitro and NeoPhos previously, before hair algae became a thing. I started dosing the Brightwell products due to my low bioload, and low nutrient issues (pale corals, little cyano when phosphates hit zero).

I plan to add a fish or two and stop dosing NeoPhos as well. I just need to be careful about having food for the coral.

The algae isn't the end of the world but I think it does irritate some of the coral (and obviously doesn't look great). It makes me perform water changes more frequently to enjoy the tank (and my nutrients are low as is).

You might want to read what 369Augold had to say May 2023.

 

[themagicman]

Looks like a fairly new tank to me. Assuming your parameters are within reason, the lighting is sufficient and a routine has been developed, (maintenance) what your seeing should subside in time. A purple nightmare so to say. (Coralline algae) GL.