Nutrients vs algae, is there a sweet spot (that's measurable)?

[IPT]

So, I have mature tank (some pieces of coral and live rock are 10+ years old (but I rebooted it bare bottom about 3 years ago with a lot of dry rock just seeding the tank with some of the old rock and some corals).

Fast forward and I am getting good SPS groth, but generally had low nutrients. Some Dino out breaks an cyano (none of these for at least 6 months maybe a year now). I had started dosing No3 and Po4 because it was chronically low. Over the last 2 weeks my values ranged .02-1.2 Po4 and No3 of 5-11 (as an example). The issue is in the last 3 months or so I started a frag tank in my sump. After adding the light I right away noticed crazy hair algae growth. Now I notice it in my overflow as well (and I never had that before).

If the so called ideal range is say .02 Po4 and 20No3 (for example), should you expect hair algae in places fish and a cleanup crew can't get to it? Am I better off reducing nutrients and running at closer to zero (knowing it can't be zero because I am dosing and feeding so there needs to actually be some in the tank)? Obviously now my algae is consuming some so my availability to tank organisms are in reality probably higher than what I measure.

I guess the main question is how do you target these parameters if there is algae present? My initial thought is to lower them (though they don't seem excessively high) . If I lower them, is one more desirable than the other to have low? I'm considering making my measurable amounts zero (knowing some is there anyway in the water from whatever minimal dosing I can do (in addition to feeding).

Thoughts, comments, suggestions? This algae (especially in the frag tank) is a PITA. of course in the display there isn't much because of my tang and rabbit fish :).

 

[slingfox]

If there is light then algae will grow if there isn’t anything around to eat it.

 

[IPT]

If there is light then algae will grow if there isn’t anything around to eat it.

Yes, maybe. Though for the first year or two I only had velonia (oh the joys) in the overflow, not hair algae. Lighting hasn't changed, but algae type and location has. Though lighting in the sump is Reefi Uno2 which is different than the rest of the tank. At first I thought it was the different spectrum, then I noticed it in the overflow too.

 

[386reeftrader]

If there's GHA then your nutrients are imbalanced. Not sure if your po4 readings was a typo .02-1.2 is a massive swing. If nutrients are fluctuating it'll slow coral growth and coralline algae which then creates more available po4/no3 and leads to unwanted algae growth. Theres's no real sweet spot for numbers, its just having a solid balance and a healthy biome. Goal is to have the corals outcompete the unwanted algae. Most reefers end up making things much worse chasing numbers to eliminate algae issues. Just remove what you can manually, add more cleanup crew and track what levels the corals do best in and focus on keeping those stable, if SPS are thriving you wont have algae issues.

 

[IPT]

If there's GHA then your nutrients are imbalanced. Not sure if your po4 readings was a typo .02-1.2 is a massive swing.

For sure - this is uncommon. I am trying to get to the source of this.

 

[IPT]

Out of curiosity, does anyone else have any hair algae in the overflow of where fish can't get to it?

 

[Orito]

Do we still believe in nutrient control to fight algae?
Predation and maturity is my answer, even the best tank will have algae where predators can't reach.

 

[slingfox]

Out of curiosity, does anyone else have any hair algae in the overflow of where fish can't get to it?

I get some growth there every so often since the area has access to water and light. No animals can access that area so algae can grow unimpeded. I clean that area up during every weekly water change. There is usually not much growth since access to light there is not great since the overflow has a lid and the grate
Of the overflow are at the back of the tank and air perpendicular to the tank light source.

 

[IPT]

Do we still believe in nutrient control to fight algae?
Predation and maturity is my answer, even the best tank will have algae where predators can't reach.

Curious, what is it about maturity you think that matters? I'd imagine you are talking about the balance of bacteria?

My tank has been setup for over 10 years, though I did a massive re-boot about 6 years ago (or something like that). Had the dinos and cyano, but haven't seen that in well over a year or more. To the best of my knowledge nothing much has changed parameter wise (except maybe more Po4?) - though I have a LOT more SPS now and in recent months I have hair algae in the overflow I have never had before? Something has changed. Maybe it some trace elements, or something.

We all know observation is the best way to notice changes in our tanks. Well, something changed but I can't pin a reason or cause for it.....hence the discussion.

 

[IPT]

I get some growth there every so often since the area has access to water and light. No animals can access that area so algae can grow unimpeded. I clean that area up during every weekly water change. There is usually not much growth since access to light there is not great since the overflow has a lid and the grate
Of the overflow are at the back of the tank and air perpendicular to the tank light source.

Yeah, I'm going to put a cover over it to minimize light. The bigger issue is a light over the sump for frags and crazy algae growth there with less herbivors.

 

[IPT]

Curious, what is it about maturity you think that matters? I'd imagine you are talking about the balance of bacteria?

My tank has been setup for over 10 years, though I did a massive re-boot about 6 years ago (or something like that). Had the dinos and cyano, but haven't seen that in well over a year or more. To the best of my knowledge nothing much has changed parameter wise (except maybe more Po4?) - though I have a LOT more SPS now and in recent months I have hair algae in the overflow I have never had before? Something has changed. Maybe it some trace elements, or something.

We all know observation is the best way to notice changes in our tanks. Well, something changed but I can't pin a reason or cause for it.....hence the discussion.

Come to think of it....I have a lot more real estate covered with coral (SPS, LPS and Zoas) than I do live rock (despite live rock in the tank and extra rock in the sump as well. Maybe adding some biomedia or more rock would be a good idea.

 

[Orito]

Curious, what is it about maturity you think that matters? I'd imagine you are talking about the balance of bacteria?

My tank has been setup for over 10 years, though I did a massive re-boot about 6 years ago (or something like that). Had the dinos and cyano, but haven't seen that in well over a year or more. To the best of my knowledge nothing much has changed parameter wise (except maybe more Po4?) - though I have a LOT more SPS now and in recent months I have hair algae in the overflow I have never had before? Something has changed. Maybe it some trace elements, or something.

We all know observation is the best way to notice changes in our tanks. Well, something changed but I can't pin a reason or cause for it.....hence the discussion.

Not just bacteria, the algae itself has a cycle, first diatom, then some green, then some hair, in the middle sometimes but nowadays much more often dinos, then finally calcareous.
Every surface in the reef will be colonized, will interact with other things like rocks and sand will absorb po4 for a good amount of time before stability, bacteria population will shift like crazy in the first years...
The reefer itself will learn to read the tank, every tank I had responded different so I believe takes time to mature.