Algae and Nutrients Misconceptions?

[matt_work27]

It seems like whenever someone has an algae issue the first thing that is asked are "What are your nitrate and phosphate levels?" When I had trouble with hair algae on the rocks my nitrates were under 10 and my phosphate weren't detectable on a salifert test kit. The first response to that is "Well, obviously you don't actually have low nutrients, the algae is just consuming it so it doesnt show up on test kit". I found the last statement to be not accurate at all in my experience. My acros were pale as is, I didn't need to further drop my nutrients through water changes or phosphate media. All I needed to do was add more alot more snails (my tank is only 50 gallons so tangs out not an option). After about 2 months of adding about 10 turbo snails to the existing populations (probably had 3 large turbos and 4 large trochus before the addition) there is literally no algae present and it even seems as though algae is growing at a slower pace, for example its takes a few days for a film algae to develop on the glass and before it was every day.
In conclusion, trying to drop your nutrients when you have an algae problem can actually kill your corals from starvation and the biggest contributing factor for algae is the lack of CUC.

One other thing to add is my tank has been setup for six years and I have about 40 pounds of well established live rock in the display and sump combined.

 

[Subsea]

It seems like whenever someone has an algae issue the first thing that is asked are "What are your nitrate and phosphate levels?" When I had trouble with hair algae on the rocks my nitrates were under 10 and my phosphate weren't detectable on a salifert test kit. The first response to that is "Well, obviously you don't actually have low nutrients, the algae is just consuming it so it doesnt show up on test kit". I found the last statement to be not accurate at all in my experience. My acros were pale as is, I didn't need to further drop my nutrients through water changes or phosphate media. All I needed to do was add more alot more snails (my tank is only 50 gallons so tangs out not an option). After about 2 months of adding about 10 turbo snails to the existing populations (probably had 3 large turbos and 4 large trochus before the addition) there is literally no algae present and it even seems as though algae is growing at a slower pace, for example its takes a few days for a film algae to develop on the glass and before it was every day.
In conclusion, trying to drop your nutrients when you have an algae problem can actually kill your corals from starvation and the biggest contributing factor for algae is the lack of CUC.

One other thing to add is my tank has been setup for six years and I have about 40 pounds of well established live rock in the display and sump combined.

Kudoes to your post.

I always recommend diversity of micro fauna & fana and for that purpose, I use diver collected live rock & live sand.

Gulf Live Rock.com

gulfliverock.com

 

[Garf]

"Well, obviously you don't actually have low nutrients, the algae is just consuming it so it doesnt show up on test kit". I found the last statement to be not accurate at all in my experience. My acros were pale as is,

That's correct, algae thrive in low nutrients. And as for the nutrients being bound in the biomass rubbish, well you'd need a lot of algae to make any noticeable difference to the results on a test kit.

 

[strich]

That's correct, algae thrive in low nutrients.

Something about this statement doesn't sit right with me. I don't think pest algae necessarily thrive specially well in low nutrients. That is to say, they don't do better than if there were a lot of nutrients right?

I think it would be more accurate to say that pest algae is very efficient and will continue to grow in low nutrient conditions where other algae (coral) will slow, starve, or die. From the outside looking in one might be mistaken for thinking that the pest algae is "killing" the other life in the tank, but it's more indirect.

Bringing it back to problem solving: The better advice might be to make sure nutrients levels stay high enough to satisfy all life in the tank as well as adding CUC to help cut down the pest blooms.

You probably already know all this, but I thought it would be interesting to get into the details and make sure the nuance is clear - Or maybe I'm wrong and I'd love to hear more!

 

[Subsea]

Something about this statement doesn't sit right with me. I don't think pest algae necessarily thrive specially well in low nutrients. That is to say, they don't do better than if there were a lot of nutrients right?

I think it would be more accurate to say that pest algae is very efficient and will continue to grow in low nutrient conditions where other algae (coral) will slow, starve, or die. From the outside looking in one might be mistaken for thinking that the pest algae is "killing" the other life in the tank, but it's more indirect.

Bringing it back to problem solving: The better advice might be to make sure nutrients levels stay high enough to satisfy all life in the tank as well as adding CUC to help cut down the pest blooms.

You probably already know all this, but I thought it would be interesting to get into the details and make sure the nuance is clear - Or maybe I'm wrong and I'd love to hear more!

This post needs to be framed in platinum. It is precisely what is counter productive with running ultra low nutrient systems. They require much finesse and rigid controls.

As a generalization, micro algae (phytoplankton) has N to P ration of 16:1 and macro algae has a N to P ratio of 30:1. It is not necessary to have that ratio in the water, it is only necessary to have sufficient concentrations. Some macro algae can absorb higher ratios of minerals and iron can even be stored for later use.

 

[ReeferFive-0]

All I needed to do was add more alot more snails

Or one urchin

 

[Reefer Matt]

I agree with a lot of this post. I often wonder if the point of micro managing nutrients is to have a nice tank, or just to have something to fixate on. I don’t worry too much about high nutrients, and have what are considered “too high” for sps coral, yet they somehow thrive. I too have a large CUC. But everyone may have a different situation, and they might not want a lot of cuc in their tank. In that case, they will probably be manually cleaning and reducing nutrients to try to prevent algae. But that is a lot of extra work compared to just buying more critters to eat it, imo.

 

[Subsea]

This post needs to be framed in platinum. It is precisely what is counter productive with running ultra low nutrient systems. They require much finesse and rigid controls.

As a generalization, micro algae (phytoplankton) has N to P ration of 16:1 and macro algae has a N to P ratio of 30:1. It is not necessary to have that ratio in the water, it is only necessary to have sufficient concentrations. Some macro algae can absorb higher ratios of minerals and iron can even be stored for later use.

Platnium Posts

[I think it would be more accurate to say that pest algae is very efficient and will continue to grow in low nutrient conditions where other algae (coral) will slow, starve, or die. From the outside looking in one might be mistaken for thinking that the pest algae is "killing" the other life in the tank, but it's more indirect.]

I agree with a lot of this post. I often wonder if the point of micro managing nutrients is to have a nice tank, or just to have something to fixate on. I don’t worry too much about high nutrients, and have what are considered “too high” for sps coral, yet they somehow thrive. I too have a large CUC. But everyone may have a different situation, and they might not want a lot of cuc in their tank. In that case, they will probably be manually cleaning and reducing nutrients to try to prevent algae. But that is a lot of extra work compared to just buying more critters to eat it, imo.

 

[Garf]

Something about this statement doesn't sit right with me.

Primary producers must thrive in low nutrients, in the sea (for example) or we wouldn't be here to debate it. I think each trophic layer biomass production must be 100 times higher than the next trophic layer, to maintain population, so that's a lot of green stuff; I think maybe the term "low nutrients" could do with defining however. The sea has nutrients below the detection limits of most / probably all hobby test kits, should we use that?

 

[matt_work27]

I agree with a lot of this post. I often wonder if the point of micro managing nutrients is to have a nice tank, or just to have something to fixate on. I don’t worry too much about high nutrients, and have what are considered “too high” for sps coral, yet they somehow thrive. I too have a large CUC. But everyone may have a different situation, and they might not want a lot of cuc in their tank. In that case, they will probably be manually cleaning and reducing nutrients to try to prevent algae. But that is a lot of extra work compared to just buying more critters to eat it, imo.

Before I added all the snails I was brushing small amounts of hair algae off the rock work every week or 2 during water changes. It felt like a never ending cycle.... Now the snails trim the hair algae as it grows. Saves me a lot of work as you mention