Randy’s Thoughts on Nutrient Target Ranges

[Randy Holmes-Farley]

I'm a way of high nutrient (phosphate at 0.576 ICP test below) and nitrate 10 and happy with it, but i should maintain the potassium and iodine high too ...

Are you asking or asserting it? I don’t think high nutrients is a reason to maintain either of those others at unnaturally high levels.

 

[rhaetuluscrenatus]

The potassium: yes because my tank uptake a lot, 20ml/ day of Red Sea trace B to keep the color (i'm chasing the colour, not the numbers), everytime i tried to reduce the potassium to below 450, many red corals become fade.
Iodine: not really, i'm dosing flatworm
Stop of KZ everyday, so explained why the iodine in my tank are so high, and no evidence of high Iodine influenced to my corals so i let it as is

Are you asking or asserting it? I don’t think high nutrients is a reason to maintain either of those others at unnaturally high levels.

 

[bakbay]

What size tank?

It’s a 90gal frag tank. Fish load is - 4 tangs, 4 clowns, and 4 damsels. Feeding: pellets, flakes, frozen, and nori.

I’ve been dosing 20mls of vodka per day (already in high concentration) for almost a month now to bring down nitrate. Bacteria is taking awhile to build & multiply.

If carbon dosing doesn’t work, I might resort to denitrator using sulfur.

 

[McPuff]

I have one of those high nutrient reefs right now. Last reading saw nitrate ~100 and phosphate just over 1. I have been slowly lowering these values over the past 6 months (yes, they were higher!) and I'd be happy to have nitrate around 50 and phosphate around 0.5. Given my bioload, I'm not sure levels much lower would be reasonably possible. Appreciate the insight you've provided.

 

[bakbay]

I have one of those high nutrient reefs right now. Last reading saw nitrate ~100 and phosphate just over 1. I have been slowly lowering these values over the past 6 months (yes, they were higher!) and I'd be happy to have nitrate around 50 and phosphate around 0.5. Given my bioload, I'm not sure levels much lower would be reasonably possible. Appreciate the insight you've provided.

I’m in the same boat actually. What’s interesting is that zoas didn’t even open for me and by lowering PO4 from 1.14 down to 0.5 (now 0.37) things started to open up. It’s just an observation since I didn’t do anything else. My nitrate is still high so trying to lower in the coming months.

 

[Randy Holmes-Farley]

The potassium: yes because my tank uptake a lot, 20ml/ day of Red Sea trace B to keep the color (i'm chasing the colour, not the numbers), everytime i tried to reduce the potassium to below 450, many red corals become fade.
Iodine: not really, i'm dosing flatworm
Stop of KZ everyday, so explained why the iodine in my tank are so high, and no evidence of high Iodine influenced to my corals so i let it as is

If a tank depletes potassium, it is certainly appropriate to maintain natural levels (~400 ppm).

That said, how are you measuring it? It is very rare for me to hear of folks saying natural levels are an issue.

 

[Miami Reef]

Do you have any thoughts on why this study found higher phosphate 0.5mg/L showed faster growth compared to 0.9mg/L and 0.20mg/L for acropora muricata?

I’d assume above 0.9mg/L wouldn’t be limited, so why how did they find phosphate concentrated had a direct correlation with growth?

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 determi…

www.sciencedirect.com

 

[exnisstech]

I also attribute a lot of "0" nutrient tanks to people running roller filters and carbon dosing... but having no clue why, other than somebody told them that is what to do. Of course then they start dumping in N and P to offset that and before you know it have their 3 month old reef upside down....

This is exactly what happened when I added a roller to one tank. I got things straightened out by shutting the roller off. I'm back to running it now but I shut it down and let it overflow several times a week. I dose AFR and do not run a skimmer and N and P are barely detectable but acros are thriving so I'm just keeping an eye on things.

 

[CHSUB]

N and P are barely detectable but acros are thriving so I'm just keeping an eye on things.

What is barely detectable? Are you expecting something to go “south”? Since low nutrients, do you make an effort to directly feed corals, for example with all pumps off and a feed tube of sorts?

 

[rhaetuluscrenatus]

If a tank depletes potassium, it is certainly appropriate to maintain natural levels (~400 ppm).

That said, how are you measuring it? It is very rare for me to hear of folks saying natural levels are an issue.

I'm using salifert besides ICP test, and the easiest way to see potassium in my tank is the Red staghorn (Bloody Mary ? ) and strawberry shortcake ,
While Kali is under 400 the red stag is fade even in blue led, shortcake has brown polyp and much more green than pink, under 450 red stag is fade in sun light but still has max red in blue led, shortcake has less red colour in sunlight (in blue led it's the same) so i tried to keep it from 450-490 , over 500 seem the shrimps are not happy with it.

 

[exnisstech]

What is barely detectable? Are you expecting something to go “south”? Since low nutrients, do you make an effort to directly feed corals, for example with all pumps off and a feed tube of sorts?

Barely detectable to me means close to zero. Last test was NO3 0.6 PO4 0.03. Tank is an acro dominant tank. I feed the corals light and fish poop. I won't win TOTM but I'm happy with the results. I dose AFR and do a 2g WC once every week or two so I can vacuum detritus. This obviously would not work for LPS which is why I removed them.

 

[Randy Holmes-Farley]

Do you have any thoughts on why this study found higher phosphate 0.5mg/L showed faster growth compared to 0.9mg/L and 0.20mg/L for acropora muricata?

I’d assume above 0.9mg/L wouldn’t be limited, so why how did they find phosphate concentrated had a direct correlation with growth?

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 determi…

www.sciencedirect.com

I don't know. They attribute it to zoox level changes, which may be different in other experiments for other reasons that impact zoox.

But a few things stand out, such as:

"No ammonia was detected at any stage of the experiment, and nitrite and nitrate levels were negligible or absent during most of the experiment."

Where is N coming from? They show a value of 0.11 to 0.13 ppm nitrate in all three phosphate cases. Maybe that is enough.

Curiously, they do not mention alkalinity at all that I could find.

 

[Randy Holmes-Farley]

I'm using salifert besides ICP test, and the easiest way to see potassium in my tank is the Red staghorn (Bloody Mary ? ) and strawberry shortcake ,
While Kali is under 400 the red stag is fade even in blue led, shortcake has brown polyp and much more green than pink, under 450 red stag is fade in sun light but still has max red in blue led, shortcake has less red colour in sunlight (in blue led it's the same) so i tried to keep it from 450-490 , over 500 seem the shrimps are not happy with it.

Assuming that is generally true, and not a systematic test issue, I can only assume the unnaturally high potassium is causing something in the coral, whether good or bad, that impacts its color. no coral in the wild ever sees 450 ppm potassium.

 

[CHSUB]

Barely detectable to me means close to zero. Last test was NO3 0.6 PO4 0.03. Tank is an acro dominant tank. I feed the corals light and fish poop. I won't win TOTM but I'm happy with the results. I dose AFR and do a 2g WC once every week or two so I can vacuum detritus. This obviously would not work for LPS which is why I removed them.

Looks very good to me! I have similar low nutrients, lower in fact, and have “great” success with LPS. However, I directly feed all corals every other day. I would describe your nutrient levels as extremely desirable with healthy fish and thriving corals.

 

[exnisstech]

Looks very good to me! I have similar low nutrients, lower in fact, and have “great” success with LPS. However, I directly feed all corals every other day. I would describe your nutrient levels as extremely desirable with healthy fish and thriving corals.

I think my lack of success with LPS is because I didn't feed enough. I did at first but for some reason I got lazy and stopped

 

[Miami Reef]

I don't know. They attribute it to zoox level changes, which may be different in other experiments for other reasons that impact zoox.

But a few things stand out, such as:

"No ammonia was detected at any stage of the experiment, and nitrite and nitrate levels were negligible or absent during most of the experiment."

Where is N coming from? They show a value of 0.11 to 0.13 ppm nitrate in all three phosphate cases. Maybe that is enough.

Curiously, they do not mention alkalinity at all that I could find.

Thank you very much. I’ve been wanting to ask you about that study for a long time!