Can high phosphate inhibit algae?

[salty joe]

Counterintuitive as it sounds, it might be true. At least one study suggested such a thing. IDK. But I do know that my Cheato crashed just about when my phosphates exploded. I guess my sand and rocks soaked up the phosphate until it couldn't.

I have some GFO on the way. I considered lanthanum chloride until I read too many credible horror stories.

I've racked my brain trying to figure out why I can't grow Cheato. Sure would be nice if the GFO did the trick!

Anyway, if anyone is interested, chime in.

 

[ya_boii]

I've noticed that it's an unstable amount of phosphates that fuel algae. I have high phosphates myself, but no algae or diatoms, for that matter. There might be some other micro nutrient that is limiting the algae. But, yeah, it's odd

Edit: also, if nitrates are too low, algae won't do well. I've been dealing with that in my tank. I finally got nitrates up a bit, and now everything seems to be running great

 

[RabidDragon]

I would consider it far more likely that your phosphates "exploded" in part because your cheato died. Algae in your tank died releasing the phosphates.

 

[CHSUB]

Ime, definitely coralline algae.

 

[salty joe]

I would consider it far more likely that your phosphates "exploded" in part because your cheato died. Algae in your tank died releasing the phosphates.

Phosphate continues to climb at a steep rate well after the Cheato gave up.

I keep up on dosing based on ATI results. And no shortage of nitrates!

 

[exnisstech]

Maybe try adding some Chaetogro? Not the same thing but I had to start dosing it after 2 of my algae scrubbers stalled. I went from not growing algae to growing this every week.

 

[areefer01]

But I do know that my Cheato crashed just about when my phosphates exploded. I guess my sand and rocks soaked up the phosphate until it couldn't.

What does 'phosphates exploded' mean and what is the number correlation?

I run both high nitrate and phosphate and have no trouble growing macroalgae. Here is what I recently exported from my refugium to my display to feed my animals. Sea Grapes, Caulerpa lentillifera.

To reference numbers last night my nitrate was 40.4 and my phosphate was 1.09 ppm.

 

[Randy Holmes-Farley Verified Community Expert]

I don’t think it likely that elevated phosphate deters any green algae unless you are talking above a few ppm phosphate.

Very high phosphate may contribute to precipitation of some trace elements such as iron, so make sure those are maintained.

 

[EnterName]

I've noticed that it's an unstable amount of phosphates that fuel algae. I have high phosphates myself, but no algae or diatoms, for that matter. There might be some other micro nutrient that is limiting the algae. But, yeah, it's odd

Edit: also, if nitrates are too low, algae won't do well. I've been dealing with that in my tank. I finally got nitrates up a bit, and now everything seems to be running great

It is actually a pretty interesting question, if...

1. ...unstable phosphate causes algae growth, or
2. ...algae growth causes unstable phosphate

(The following is completely speculative, so don't quote me on that)
Scenario 1 could be explainable if unstable phosphate stops corals from consuming it. This would give algae a chance to establish as there is less competition over nutrients. Corals don't seem to like sudden changes in phosphate very much and often stay closed for a while afterwards, so I assume this might be an actual possibility and could even explain how algae growth can take over in low nutrient environments.

Scenario 2 still seems a bit more logically to me, as algae growth first reduces phosphate until a lack of trace elements/vitamins/etc. stops the process letting phosphate accumulate again. Depending on added supplements, water changes, etc. this process might repeat over and over making phosphate appear all over the place.

 

[Subsea]

Counterintuitive as it sounds, it might be true. At least one study suggested such a thing. IDK. But I do know that my Cheato crashed just about when my phosphates exploded. I guess my sand and rocks soaked up the phosphate until it couldn't.

I have some GFO on the way. I considered lanthanum chloride until I read too many credible horror stories.

I've racked my brain trying to figure out why I can't grow Cheato. Sure would be nice if the GFO did the trick!

Anyway, if anyone is interested, chime in.

What peer review study are you referring too? Please provide link.,

 

[Garf]

What peer review study are you referring too? Please provide link.,

Here’s an oldish one, about growth being reduced when the accumulation in tissues is very high;

The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae - PMC

The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef ...

pmc.ncbi.nlm.nih.gov

 

[areefer01]

I probably should have noted but I do dose a tiny bit of ESV Transition Elements which contains Iron. May, or may not, be a factor but hey, honesty in reefing.

 

[Subsea]

Here’s an oldish one, about growth being reduced when the accumulation in tissues is very high;

The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae - PMC

The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef ...

pmc.ncbi.nlm.nih.gov

I read the whole thing and it was quite detailed. The graph above was for one species only:

“L. intricata, growth rates varied significantly with tissue %P (ANOVA, F(7,25) = 2.975, P = 0.029) in a unimodal relationship with peak growth attained in algae with tissue P concentrations of 0.21% (Fig. 6).”

However, the other Macroalgaes in the study did not reflect stunted growth with very high phosphate. The excess uptake of this group was called “luxury” uptake to be used later when phosphate was low in the water column. Similar to iron storage to be used when iron was low in water column.

First sentence of first paragraph in discussion section:

“Elevating nutrient levels did not result in increased growth rates in any of the macroalgal species in our experiments. However, the algae did respond positively in other ways to nutrient additions, which contradicts the possibility of nutrient toxicity.”

 

[Randy Holmes-Farley Verified Community Expert]

Folks should not misinterpret the above graph. It is not a plot of growth vs phosphate in the water. That graph is tissue phosphate.

while they do show that added P reduces short term growth, remember they took algae from an environment with low P (open ocean) and then flooded them with P. Organisms grown in higher P solutions may have a very different effect.

Imagine a starving person dropped at an all you can eat buffet. They will almost certainly overeat and suffer unpleasant effects.,

 

[Subsea]

Randy,
Is 0.215% the same as 2,150 ppm.

 

[mcarroll]

Counterintuitive as it sounds, it might be true. At least one study suggested such a thing. IDK. But I do know that my Cheato crashed just about when my phosphates exploded. I guess my sand and rocks soaked up the phosphate until it couldn't.

I have some GFO on the way. I considered lanthanum chloride until I read too many credible horror stories.

I've racked my brain trying to figure out why I can't grow Cheato. Sure would be nice if the GFO did the trick!

Anyway, if anyone is interested, chime in.

It's hard to imagine how this would be true, but it's an interesting thought!

Can you share more details on why you think this? Also link or title for the study would be most welcome.

Would be interested to know your water test results, especially no3, po4, s.g., and temperature....as well as a little background on the tank where this is happening.

 

[Garf]

I read the whole thing and it was quite detailed. The graph above was for one species only:

“L. intricata, growth rates varied significantly with tissue %P (ANOVA, F(7,25) = 2.975, P = 0.029) in a unimodal relationship with peak growth attained in algae with tissue P concentrations of 0.21% (Fig. 6).”

However, the other Macroalgaes in the study did not reflect stunted growth with very high phosphate. The excess uptake of this group was called “luxury” uptake to be used later when phosphate was low in the water column. Similar to iron storage to be used when iron was low in water column.

First sentence of first paragraph in discussion section:

“Elevating nutrient levels did not result in increased growth rates in any of the macroalgal species in our experiments. However, the algae did respond positively in other ways to nutrient additions, which contradicts the possibility of nutrient toxicity.”

Although the paper actually indicates all 3 species were negatively effected in regards to growth, nothing died. And the "Control" samples were also negatively effected by something. See below. I was an avid algae googler a long time ago and I think this is the only paper I came across suggesting such an effect. I'm guessing this is the one the OP is refering to.

 

[mcarroll]

The chart is also intriguing, but unless I'm doing something wrong I don't see a clickable link or title. Maybe the author?

 

[Subsea]

Although the paper actually indicates all 3 species were negatively effected in regards to growth, nothing died. And the "Control" samples were also negatively effected by something. See below. I was an avid algae googler a long time ago and I think this is the only paper I came across suggesting such an effect. I'm guessing this is the one the OP is refering to.

Again, I did not came to the same conclusion.

As a marine engineer, I am not a scientist. I do read peer reviewed articles. It was ambiguous to me and requires much more study.

 

[Garf]

The chart is also intriguing, but unless I'm doing something wrong I don't see a clickable link or title. Maybe the author?

Post #11