I'm dying on this hill - Phosphate is more important than alkalinity

[good.reef]

Honestly I’m a strong believer if your tank looks good let it ride regardless of the numbers. If you chase numbers you can find yourself dosing this and that to meet the “recommended levels” and run into other problems. I test once a week and yes sometimes I find things out of the relative norm. But if things look good I leave it alone and stick to my normal water change maintenance

I agree. But so many people seem obsessed with their numbers I'm just wondering if they enjoy that aspect or if it's more out of fear?

 

[PhantomHalo]

What are you dosing to bring your phosphate levels up?

 

[AgentSPS]

I’ve found that chasing numbers has more often than not had negative results for me. My parameters don’t match what other people have successfully run their systems at but I have success. When testing (and I test fairly regularly), I put most emphasis on keeping levels consistent with what I have found works for me.

So when people ask me for advice, I say to them to do what works best for them and stick with it.

 

[KrisReef]

I test so I can know what the nutrients levels are testing at. As things change I adjust to keep the corals fed. If I don't test then I am guessing that levels are ok and that works until it doesn't.

I recently brought home a piece of dry rock and dropped it in a bucket with RODI (tested zero Phosphates to start). I retested in a week and got 4ppb (HannaULR). Retested a week after that and got 15ppb.

Hypothesis: Phosphate in reef tanks settles on substrates. Dosing may not cause steady measurable increases as the phosphate present is apparently absorbed by the rock in the system. When the system reaches capacity to accommodate phosphate then dosing a small amount could cause significant non-linear concentration increases.

 

[S.Pepper]

What are you dosing to bring your phosphate levels up?

I'd like to know that too.

 

[Potatohead]

What are you dosing to bring your phosphate levels up?

Trisodium phosphate. 1.88 grams dissolved into 1L of water will make 0.01 ppm in 100L (26 gallons) of water per 1 ml dosed.

In terms of chasing numbers, I've never really tried to do it. My tank just simply settled where it did in terms of nutrients, and for some reason it uses a lot of phosphate. I would always test between about 2 and 8 on the Hanna ULR which I tested maybe 2-3 times a month. As I said in the OP everything was OK, but not thriving. I could see it, I wasn't going off numbers.

This is a little embarrassing to admit, but where I went wrong (which is what Brandon was alluding to earlier) is I have literally been dealing with dinos in my sand for over two years. Because they are red, I always thought it was cyano. So I thought my phosphate was low because the cyano was using it up, so I spent like two years trying various things to beat this apocalyptic cyano. So if the cyano was using the phosphate, I never considered actually dosing phosphate because that would just make cyano worse, right? It wasn't until I read the dinos thread that everything changed. I must have skipped past that thread every day for eighteen months or more. Dinos are brown snotty bubbly thing right? Well I don't have that... What a maroon.

That was about four or five weeks ago and today my tank is very different, for the better. Everything is healthier, growing faster, colored better, and about 2/3 of the dinos to this point are gone.

 

[Potatohead]

I test so I can know what the nutrients levels are testing at. As things change I adjust to keep the corals fed. If I don't test then I am guessing that levels are ok and that works until it doesn't.

I recently brought home a piece of dry rock and dropped it in a bucket with RODI (tested zero Phosphates to start). I retested in a week and got 4ppb (HannaULR). Retested a week after that and got 15ppb.

Hypothesis: Phosphate in reef tanks settles on substrates. Dosing may not cause steady measurable increases as the phosphate present is apparently absorbed by the rock in the system. When the system reaches capacity to accommodate phosphate then dosing a small amount could cause significant non-linear concentration increases.

Rock and sand definitely holds phosphate, and a lot of it. I believe Randy HF said 100 lbs of rock will hold something ridiculous, like 50,000 ppm.

 

[gotmesalty77]

So i have been conducting a secret experiment on my po4 levels since iam trying to rehab a bleached non acclimated wilsoni to a tropical tank. Those things eat like there is no tomrrow and i do my best to target feed but this extra feeding has shot my po4 to levels that have been outright terrifying but everything in the tank as seemed to love it.

 

[Ross Petersen]

I feel the opposite. My issues have always come from a sudden change due to some random event (mess up) or low readings. When my po4 is in the 0.01-0.02 range I feel I am playing a dangerous game. Never have I see SPS go south faster than ones in a tank with lack of po4. I'd say since I started keeping SPS in 2008, lack of po4 has been the biggest killer by far.



My Alk has been 7.5-8.9 consistently for the last 4 years, one time when I was out of town for work I believe my cat got into my fish room and rubbed it's face all over my aquarium plants co2 regulator knob (lots of cat hair in that area). It was a perfect storm because my Apex also failed and left the co2 regulator ON even though the entire rest of the bar was out (go figure). Like it was like winning the lottery of bad luck...

Anyway, my Alk shot up to 14.8 before I had my wife take it down. I only found out when my Apex for some odd messed up reason SMS txted my randomly 6 hours after it happened to tell me my pH was off. The tank is jam packed with SPS so I figured i'd come home to a mess. When I got home and slowly peeked around the corner expecting the worst everything looked fine. I worked to get it back down and screwed up again as I was stressed from work and this fiasco, I went to get it back down and forgot I turned everything off after my water change. 2 days later my alk was 4.5.

My tank went from 7.8 to 14.5 in 5 hours, from 14.5 back to 12.5 in 2 days the over the next two days down to 4.5 and then back to it's normal 7.8 over the next 4 days or so. I never noticed a single thing other than some slightly cloudy water and poor PE for a few days.

Meanwhile, this month I lost my first SPS in 4 years because of a nitrate spike that depleted all my po4.

Random side question - why does phosphate drop when nitrates spike?

 

[living_tribunal]

My tank has been running for about three years. It is acro dominated and for the most part has done ok. I have always thought my growth was a little slow, and colors were just alright. Maybe like a C+ grade.

My parameters are always quite stable, and I run my alkalinity in the low 7's. I have experimented slowly raising it to the mid 8's for a few months and really noticed hardly any difference, but because it didn't seem any better I slowly dropped it back down. My nitrate is pretty much always 4-5 and my phosphate was always .01-.02 range. I knew this was perhaps slightly low but still in acceptable range.

In my quest to deal with some dinos in the sand, since I had a spare head on my doser, about four weeks ago I started dosing phosphate. I started at dosing about .06 per day. Four weeks later I am dosing .2 per day, which is actually maintaining about .06 actually in the water.

The difference in my corals is profound. Color, polyp extension, growth, all seemingly exploded in about a week. Coralline growth has probably doubled as well. Euphyllia much puffier and also growing faster.

There is probably some bias here, and this probably differs based on each individual tank... But the difference I am seeing based on phosphate levels compared to alkalinity level, and even alkalinity stability is immense.

I and several others have become major proponents of both "elevated" phosphate levels and changing the narrative on their importance.

Too late to get into it but some of the new research coming out shows signifiantly faster growth for corals in high phosphate levels (albeit with a ~17% more porous skeleton).

What we're learning is that nitrate stunts coral development and only trace amounts are required. Corals under low nitrate and high phosphate conditions have nearly identical zoox efficiencies, calcification volumes, and polyp extension as those in replete conditions. Corals will tolerate an even thrive under extremely high phosphate levels while they are stressed under high nitrate low phosphate levels.

An additional study tested calcification of acropora at various phosphate levels. The results speak for themselves. Acros had expontentially faster growth at the highest phosphate level of .5.

This is not a system for everyone but so far I really like how it's working in my tank. I don't want to force this on anyone else, everyone has their own preferred methods and I 100% respect that. However, I've been experimenting with a high phosphate low nitrate system for the last 4 months and have noticed a remarkable difference in growth and health, no algae or cyano in sight. I know there is probably quite a bit we still need to learn and there are many unknowns.

I might make a build thread on it when I can get things in my system back to normal after my temperate wilso is acclimated.

Sources:

New study documents increased growth of staghorn Acropora in higher phosphate levels | Reef Builders | The Reef and Saltwater Aquarium Blog

Acropora corals are a mysterious creature with complex needs and one of those that we thought we’d nailed long ago was their “need” for minimal phosphate concentration in the water. A new study by…

reefbuilders.com

Nutrients and coral growth: Nitrogen impairs, but Phosphorus aids

New From our friends over at the Burkepile Lab at Florida International University - It's been communicated many times that nutrient pollution of the oceans can affect the performance of various coral species. To date, the results have been varied…researchers find different responses, but they...

appliedecology.cals.ncsu.edu

Limited phosphorus availability is the Achilles heel of tropical reef corals in a warming ocean - Scientific Reports

During the 20th century, seawater temperatures have significantly increased, leading to profound alterations in biogeochemical cycles and ecosystem processes. Elevated temperatures have also caused massive bleaching (symbiont/pigment loss) of autotrophic symbioses, such as in...

www.nature.com

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates

Enrichment of reef environments with dissolved inorganic nutrients is considered a major threat to the survival of corals living in symbiosis with dinoflagellates (Symbiodinium sp.). We argue, however, that the direct negative effects on the symbiosis ...

www.ncbi.nlm.nih.gov

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach | Request PDF

Request PDF | Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach | Phosphate contamination can negatively affect corals, modifying growth rates, skeletal density, reproduction, mortality, and zooxanthellae. We... |...

www.researchgate.net

 

[living_tribunal]

For those of you that concentrate on the numbers so closely, is it an enjoyable part of the hobby for you? I'm genuinely curious because I hate testing and trying to tune into numbers but only because I find it boring. I leave my tank be and respond if something seems to not be well. I'm definitely not saying my way is better, it works for me and it's just how I enjoy the hobby. I see people post spread sheets and formulas and exact parameters and stress when they are .0X off and it makes me cringe because I wouldn't enjoy the hobby that way. So my question is for those of you that like to test frequently and keep exacting water results, do you do it because you enjoy that part of it or are you afraid the tank will fail if you don't do it that way?

I enjoy working on my tank. The benefits of seeing things grow fast means a lot more to me than taking 5-10 min to test every other day.

 

[KleineVampir]

To be honest, with my rocks and nutrient problem, I resent anybody who doses phosphates! Do you guys dose nitrates too? xD I got a supplement for you. My water!

 

[Ross Petersen]

I and several others have become major proponents of both "elevated" phosphate levels and changing the narrative on their importance.

Too late to get into it but some of the new research coming out shows signifiantly faster growth for corals in high phosphate levels (albeit with a ~17% more porous skeleton).

What we're learning is that nitrate stunts coral development and only trace amounts are required. Corals under low nitrate and high phosphate conditions have nearly identical zoox efficiencies, calcification volumes, and polyp extension as those in replete conditions. Corals will tolerate an even thrive under extremely high phosphate levels while they are stressed under high nitrate low phosphate levels.

An additional study tested calcification of acropora at various phosphate levels. The results speak for themselves. Acros had expontentially faster growth at the highest phosphate level of .5.

This is not a system for everyone but so far I really like how it's working in my tank. I don't want to force this on anyone else, everyone has their own preferred methods and I 100% respect that. However, I've been experimenting with a high phosphate low nitrate system for the last 4 months and have noticed a remarkable difference in growth and health, no algae or cyano in sight. I know there is probably quite a bit we still need to learn and there are many unknowns.

I might make a build thread on it when I can get things in my system back to normal after my temperate wilso is acclimated.

Sources:

New study documents increased growth of staghorn Acropora in higher phosphate levels | Reef Builders | The Reef and Saltwater Aquarium Blog

Acropora corals are a mysterious creature with complex needs and one of those that we thought we’d nailed long ago was their “need” for minimal phosphate concentration in the water. A new study by…

reefbuilders.com

Nutrients and coral growth: Nitrogen impairs, but Phosphorus aids

New From our friends over at the Burkepile Lab at Florida International University - It's been communicated many times that nutrient pollution of the oceans can affect the performance of various coral species. To date, the results have been varied…researchers find different responses, but they...

appliedecology.cals.ncsu.edu

Limited phosphorus availability is the Achilles heel of tropical reef corals in a warming ocean - Scientific Reports

During the 20th century, seawater temperatures have significantly increased, leading to profound alterations in biogeochemical cycles and ecosystem processes. Elevated temperatures have also caused massive bleaching (symbiont/pigment loss) of autotrophic symbioses, such as in...

www.nature.com

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates

Enrichment of reef environments with dissolved inorganic nutrients is considered a major threat to the survival of corals living in symbiosis with dinoflagellates (Symbiodinium sp.). We argue, however, that the direct negative effects on the symbiosis ...

www.ncbi.nlm.nih.gov

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach | Request PDF

Request PDF | Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach | Phosphate contamination can negatively affect corals, modifying growth rates, skeletal density, reproduction, mortality, and zooxanthellae. We... |...

www.researchgate.net

Ahhh... technical science. Love this!

 

[living_tribunal]

Ahhh... technical science. Love this!

Trying to now translate it into application. Will be interesting to see how it works out long-term.

For anyone interested, I'm running nitrate of .5-1 and phosphate of .15. I'm able to keep levels +- 10% at all times via vinegar dosing and fuge, that's all.

 

[Ross Petersen]

Trying to now translate it into application. Will be interesting to see how it works out long-term.

I gather you are in this field of study? I did the neuroscience grad school thing... and think it would be pretty neat to do some more academic work in the marine hobby world. So many angles to explore.

 

[Potatohead]

Random side question - why does phosphate drop when nitrates spike?

Denitrifying bacteria use all three nitrogen/carbon/phosphorous to grow. If you keep your tank pretty stable you will have a pretty stable mass of these bacteria. If something happens that suddenly adds a bunch of nitrogen and carbon to the tank, but not much phosphorous, the bacteria mass will grow as big as it can trying to consume the N and C but it will eventually run out of P.

This is why some people prefer to feed more rather than dosing individual elements because with food your are adding all three. I actually agree with this but when you get out of balance you need to add one by itself to correct. So in the above scenario you can add phosphorous alone to feed the bacteria again which will reduce the nitrate back down. This is the whole premise of carbon dosing because typically our tanks are carbon limited.

 

[Ross Petersen]

Denitrifying bacteria use all three nitrogen/carbon/phosphorous to grow. If you keep your tank pretty stable you will have a pretty stable mass of these bacteria. If something happens that suddenly adds a bunch of nitrogen and carbon to the tank, but not much phosphorous, the bacteria mass will grow as big as it can trying to consume the N and C but it will eventually run out of P.

This is why some people prefer to feed more rather than dosing individual elements because with food your are adding all three. I actually agree with this but when you get out of balance you need to add one by itself to correct. So in the above scenario you can add phosphorous alone to feed the bacteria again which will reduce the nitrate back down. This is the whole premise of carbon dosing because typically our tanks are carbon limited.

Thank you. This is invaluable detail and gives me some ideas for projects in my science class.

 

[Tastee]

For those of you that concentrate on the numbers so closely, is it an enjoyable part of the hobby for you? I'm genuinely curious because I hate testing and trying to tune into numbers but only because I find it boring. I leave my tank be and respond if something seems to not be well. I'm definitely not saying my way is better, it works for me and it's just how I enjoy the hobby. I see people post spread sheets and formulas and exact parameters and stress when they are .0X off and it makes me cringe because I wouldn't enjoy the hobby that way. So my question is for those of you that like to test frequently and keep exacting water results, do you do it because you enjoy that part of it or are you afraid the tank will fail if you don't do it that way?

I wouldn’t say I am in love with water testing but I do keep close tabs on N/P after taking 12 months to deal with GHA on my first tank and wanting to get a better understanding of my tank behaviour and these two parameters. I’m not chasing any particular numbers but are very gradually making changes and monitoring progress. At the moment, based on everything I have read, I am trying to maintain or even reduce my N/P ratio as after 12 months of no changes I saw that start to rise and a little more unwanted algae develop.

So for me it’s more about learning about my tank than it is chasing any particular numbers.

 

[Hans-Werner]

If phosphate is the limiting nutrient, at 0.01 to 0.02 ppm phosphate it is, alkalinity higher than 7° dKH is of no use. In contrary most probable it will worsen things and may induce STN of SPS from the base.

In my opinion 0.05 to 0.1 ppm of phosphate is the safest range. You have at least 0.04 ppm range before it is really getting bad.

However, dropping phosphate concentrations may always be a problem. In contrast rising phosphate concentrations hardly ever will cause problems and only with extremely high concentrations. The problems will occur when you lower phosphate concentrations again. SPS adapt to high phosphate concentration rapidly but are really bad in adapting to lower phosphate concentration.

Skeletons of SPS show quite high phosphate concentrations (even at low phosphate concentrations in the water). Phosphate is located mainly in the organic matrix. Obviously phosphate plays a crucial role in skeletal growth. Especially the fast growing SPS need a lot of phosphate and now it also gets clear why raising alkalinity at low phosphate concentrations has such a detrimental effect.

At higher phosphate concentrations also higher alkalinities may have a positive effect for coral growth, but only then.

 

[Nicholas Dushynsky]

I was slowly losing my sps coral and put it down to alk being around 6.8-7.2. I then learnt that it was zero phosphates and very low nitrates. The sps was getting pale then stn, my lps were also not as puffy, I now dose potassium phosphate at a dose of 1.3mm on my system (90litre) 0.08 every other day as I don't want to over do it. The tank looks happier just still not as puffy as I'd like.
Does anyone know to what level you can raise per day? I'm assuming there are other organisms within the tank that use phosphates other than corals, and I assume that the rocks and sand bind some also. I am just wandering if the tank will reach a balance and dosing will only be required occasionally not all the time or is it a case that's it full time and on a doser? This is all fairly new to me.