Nitrates and phosphates

[John3]

I’m wondering what the relationship is to each other in terms of nutrients to corals. I currently have nitrates 10-15ppm which my corals like. If I let them drop below 10 my lps shrinks up some and my zoas will partially close. My phosphates test at 0 with an api kit which I know is not a good test. I have almost no algae on my rock work anymore and I only need to clean my glass twice a week. So it seems my phosphates are indeed low.

I’ve seen many people say they like their nitrates 3-5ppm. I’m wondering if my corals look bad when I drop below 10 because I am very low on phosphates. So if my phosphates came up some maybe I could lower my nitrates towards 5? I really need to do a good test on phosphates to confirm my level but I was wondering if there is a known relationship/balance with them and nitrates.

Thanks, John

 

[NY_Caveman]

Not saying I follow this to a T, but check out the Redfield Ratio. 16:1 Nitrogen : Phosphorous off my head. But I am no expert on this or its usefulness.

 

[NY_Caveman]

https://en.wikipedia.org/wiki/Redfield_ratio

 

[madweazl]

If your inhabitants look good at this point, why would you change anything? If anything, grab a quality test kit for your phosphates, note where they're at, and strive to keep them there (again, provided what you have actually is healthy). Dont arbitrarily change something just because somebody else has good results with a different number.

 

[jda]

I would not mess with what is working, but test, record and observe so that you know where you came and the trend line if you start to dislike things.

Before you do anything, get a Hannah HI736 Ultra Low Phosphorous Checker so that you know where your phosphates are. You do not have to have low N and P to keep algae down.

With the Redfield Ratio, remember that phosphorous and phosphate are different. I am close to it, but not exact. .1N and .005P, or about 15:1. Our test kits are not all that accurate in this range, so who knows.

 

[John3]

Almost everything does look good except a few acans. They seem very touchy in regards to the nitrate level. I’m kinda wondering if my phosphate level is the main issue. Maybe when my nitrates get below 10 my phosphates are truly going to nothing.

This wasn’t so much an issue til the last couple months when I switched over from feeding just frozen food to now mostly pellet food with the occasional frozen treat. My smaller algae issues also disappeared during this same time frame. Gha gone, brown film algae mostly gone. Clean up crew is scrounging for food.

My other corals are looking and growing very well. I have a candy cane that is a little bigger than a baseball that just keeps getting bigger. Favia looks good. Zoas are spreading like fire. Mushrooms are getting bigger. I have a orange monti that is growing so fast I’m gonna need to groom it fairly frequently if it keeps going like this. So the acans gave me scratching my head. Somehow it ties into the nitrates but 5 ppm seems good for others with acans, just not for me. So I wonder why.....

 

[jda]

If you are under 20N, I would look lights for big changes. You can have more impact with coral food (lights) than you can with water quality if you are in the ballpark. I would take ballpark water and excellent lights over excellent water and so-so lights.

Honestly, everybody has a trouble coral, or two, that are just blah for them... for me it is Rogue Millepora. Do not risk the others chasing those one or two corals... unless they are your dream corals.

Are you changing some water to keep the trace/minor elements in the tank? This can sometimes be an easy fix with LPS and softies.

Keep those cleaners fed... they cannot live on poo alone. You do not want them to die.

 

[John3]

I do weekly 15% changes with rodi water. I’ve been using reef crystals for about 7-8 months now.

The acans are not make or break for me but they are my wife’s favorite. They used to grow very well prior to s couple months back.

Im running a radion g4 with the AB+ schedule at 70%. I have been running this schedule for 7-8 months now.

 

[jda]

You are probably fine. I anything, I would monitor the levels and record everything. ...maybe add some T5s to the Radions to help with coverage and spectrum.

 

[pga7602]

The test kit you are using fir phosphate may not be accurate enough to detect such low levels.

 

[hatfielj]

The redfield ratio has nothing to do with the ratio of nitrates to phosphates in the water. It’s the ratio that is used by organisms and found in their tissues. Two different things No one knows what the ideal ratio for reef tanks is (if there is an ideal).

 

[NY_Caveman]

The redfield ratio has nothing to do with the ratio of nitrates to phosphates in the water. It’s the ratio that is used by organisms and found in their tissues. Two different things No one knows what the ideal ratio for reef tanks is (if there is an ideal).

Thanks for the distinction!

 

[Randy Holmes-Farley Verified Community Expert]

I’m wondering what the relationship is to each other in terms of nutrients to corals. I currently have nitrates 10-15ppm which my corals like. If I let them drop below 10 my lps shrinks up some and my zoas will partially close. My phosphates test at 0 with an api kit which I know is not a good test. I have almost no algae on my rock work anymore and I only need to clean my glass twice a week. So it seems my phosphates are indeed low.

I’ve seen many people say they like their nitrates 3-5ppm. I’m wondering if my corals look bad when I drop below 10 because I am very low on phosphates. So if my phosphates came up some maybe I could lower my nitrates towards 5? I really need to do a good test on phosphates to confirm my level but I was wondering if there is a known relationship/balance with them and nitrates.

Thanks, John

What do you do to "let them drop below 10"?

Some things you might do will have other consequences as well, and the results may not be from the nitrate level.

 

[John3]

I dosed VC for a little bit and the nitrates dropped to 5. I stopped dosing VC but now I need to feed more than before just to keep my nitrates around 15. I used to change my filter sock more often as well but now I need to leave it in longer to keep my nitrates around 15. I’m feeding prob twice as much as I used to for the same fish and cuc population.

I’m guessing I may still have a bacteria colony that is consuming the nitrates. It used to be very tough to keep my nitrates below 20 but now it’s the opposite. On the plus side my tank shows almost no pest algae.