Dosing no3. Po4 falling?

[Michael Gray]

Is there a correlation with dosing po4 and no3.

My tank has been testing 0 po4 with hanna phosphorus ulr low checker. And 0 no3 with red sea pro test kit. I was dosing microbacter 7 to help with GHA. Since then for about 5 days now I stopped dosing any MB7. I also changed skimmer settings just a hair. Turned it to skim slightly dryer.

Every day at noon I test. My po4 started showing a reading.
Day 2.
Po4 9ppb / no3 0
Dosed a couple ml NO3

Day 3
Po4 12ppb
NO3 under .25ppm
Dosed NO3

Day 4
Po4 14ppb or .043ppm
NO3 under .25ppm
Dosed about 6ml NO3

Day 5
Po4 12ppb
NO3 est. .25ppm still
Dosed 6ml NO3

Day 6
Po4 9ppb
NO3 around .50-.75ppm
Dosed a little more to get to 2ppm-4ppm

My dosing is working to slowly lift NO3.

My question is dosing No3 cause Po4 to fall in an aquarium? Is this the correlation between to the two? Wondering if po4 drops to 0 if I dose a small po4 will no3 drop slightly and just gotta find a good consistent balance?

Thanks for the help and I apologize if I'm making zero sense.

 

[Larry L]

My question is dosing No3 cause Po4 to fall in an aquarium? Is this the correlation between to the two?

Yes, growth of coral or algae depends on the existence of both nitrates and phosphates, so growth slows or stops if one or the other is lacking. In your case once you start providing the missing nitrates, growth increases, which means you'll be depleting phosphates faster than when growth was slow.

 

[Michael Gray]

Ok. So when I get nitrates to where I'd like them....phosphates will have to be dosed to the correct level that I'm looking for. and try to keep it consistent

 

[LARedstickreefer]

Increasing nitrates will fuel life that needs both nitrates and phosphate. If phosphate drops with increased nitrates, then you were nitrate limited.

This is why dosing either isnt the best for the long run; you’ll chase both.

 

[Randy Holmes-Farley Verified Community Expert]

Increasing nitrates will fuel life that needs both nitrates and phosphate. If phosphate drops with increased nitrates, then you were nitrate limited.

This is why dosing either isnt the best for the long run; you’ll chase both.

I don't get that last point at all.

If you want them both at a certain level, why isn't dosing among the best ways to get there?

The N and P target levels themselves may be suspect, but no other way of attaining them will alter what organisms do with it.

 

[Randy Holmes-Farley Verified Community Expert]

Ok. So when I get nitrates to where I'd like them....phosphates will have to be dosed to the correct level that I'm looking for. and try to keep it consistent

N or P may be limiting, but it also can be other things (such as iron). I don't see people having a big problem attaining reasonable levels with some dosing or one, rarely both.

 

[LARedstickreefer]

I don't get that last point at all.

If you want them both at a certain level, why isn't dosing among the best ways to get there?

The N and P target levels themselves may be suspect, but no other way of attaining them will alter what organisms do with it.

I meant that dosing one will eventually require dosing the other, or the other will become the limiting factor. If you just don’t nitrates, phosphate will bottom out, and vice versa.

Food contains both.

 

[Michael Gray]

I feel like I feed alot though. I dont even turn off powerheads anymore so it just blows around hoping it gets stuff in rocks lol.

 

[Randy Holmes-Farley Verified Community Expert]

I meant that dosing one will eventually require dosing the other, or the other will become the limiting factor. If you just don’t nitrates, phosphate will bottom out, and vice versa.

Food contains both.

Lots of people find they only need to dose nitrate, and that may be because of denitrification reducing it but not phosphate.

 

[BeejReef]

Great scientific approach, but you are going to drive yourself crazy testing at those ranges and making adjustments daily. You might be better served continuing with your methodology, but weekly.

 

[LARedstickreefer]

Lots of people find they only need to dose nitrate, and that may be because of denitrification reducing it but not phosphate.

Don’t Bactria, and other organisms, require phosphate?

 

[Michael Gray]

Great scientific approach, but you are going to drive yourself crazy testing at those ranges and making adjustments daily. You might be better served continuing with your methodology, but weekly.

Well I def dont plan on this daily just since I added acros I'm tested daily just to raise it then I'll probably test 2 times a week. Then 1 time if I can keep po4 and no3 in system

 

[Michael Gray]

Another question for the pros.

Still dosing no3 which is now around 1.5ppm and daily adding no3 longer to 2 to 4ppm. And dosed po4 slightly to now .03-.04. Now my question is. Ia any of thia relative to my alk climbing let's say .4dkh in the last 4 days or so? Tested 2 times today at same time 9.4 and 9.2 with hanna checker

I do dose 2 part with ghl doser. I havent changed the settings for over 1.5months. And it was consistent. Held 8.7dkh same time everyday. I added alot of sps frags since but wondering why alk potentially rising without dosing anymore than I have. Especially with sps now added.

Before I change my dosing down slightly I'd figure I would ask

 

[LARedstickreefer]

Another question for the pros.

Still dosing no3 which is now around 1.5ppm and daily adding no3 longer to 2 to 4ppm. And dosed po4 slightly to now .03-.04. Now my question is. Ia any of thia relative to my alk climbing let's say .4dkh in the last 4 days or so? Tested 2 times today at same time 9.4 and 9.2 with hanna checker

I do dose 2 part with ghl doser. I havent changed the settings for over 1.5months. And it was consistent. Held 8.7dkh same time everyday. I added alot of sps frags since but wondering why alk potentially rising without dosing anymore than I have. Especially with sps now added.

Before I change my dosing down slightly I'd figure I would ask

So your alkalinity has gone up without dosing anything that adds it? Has your salinity gone up?

 

[Michael Gray]

So your alkalinity has gone up without dosing anything that adds it? Has your salinity gone up?

I dose 2 part but havent changed amounts in about 1.5 months.

The last week it has gone up about .5dkh.

My numbers arent bad but now that I have acros I dont want the swing. Numbers as of today are 9.3dkh and 420ca. About 4 to 5 days ago it was 8.7-8.8

I dose brs 2 part. But havent upped the dosage. And it was pretty steady. Really steady.

Only thing I changed was started dosinf potassium nitrate for last 7 days. Or so and like 1ml of po4 to up it a tad.

I know dont chase numbers. 9dkh and 425ca would be my magic number but most important this slight swing is only bothering me because of sps now. I dont want the swing all of a sudden

 

[LARedstickreefer]

I dose 2 part but havent changed amounts in about 1.5 months.

The last week it has gone up about .5dkh.

My numbers arent bad but now that I have acros I dont want the swing. Numbers as of today are 9.3dkh and 420ca. About 4 to 5 days ago it was 8.7-8.8

I dose brs 2 part. But havent upped the dosage. And it was pretty steady. Really steady.

Only thing I changed was started dosinf potassium nitrate for last 7 days. Or so and like 1ml of po4 to up it a tad.

I know dont chase numbers. 9dkh and 425ca would be my magic number but most important this slight swing is only bothering me because of sps now. I dont want the swing all of a sudden

Ah, ok so you are adding two part. I’d suspect that your corals have slowed their uptake of alkalinity then.

 

[Erasmus Crowley]

I dose 2 part but havent changed amounts in about 1.5 months.

The last week it has gone up about .5dkh.

My numbers arent bad but now that I have acros I dont want the swing. Numbers as of today are 9.3dkh and 420ca. About 4 to 5 days ago it was 8.7-8.8

I dose brs 2 part. But havent upped the dosage. And it was pretty steady. Really steady.

Only thing I changed was started dosinf potassium nitrate for last 7 days. Or so and like 1ml of po4 to up it a tad.

I know dont chase numbers. 9dkh and 425ca would be my magic number but most important this slight swing is only bothering me because of sps now. I dont want the swing all of a sudden

When ammonia is converted to nitrate, it consumes alk. When nitrate is used by biological processes, it releases that alk back into the water. Dosing nitrate directly, which is then used up in the tank, will raise alk as it is consumed.

Relevant Randy post: https://www.reef2reef.com/threads/alkalinity-rising-from-dosing-nitrate.365780/#post-4522730

 

[Michael Gray]

When ammonia is converted to nitrate, it consumes alk. When nitrate is used by biological processes, it releases that alk back into the water. Dosing nitrate directly, which is then used up in the tank, will raise alk as it is consumed.

Relevant Randy post: https://www.reef2reef.com/threads/alkalinity-rising-from-dosing-nitrate.365780/#post-4522730

Ok so this should be temporarily. As I dont plan to dose daily. Maybe I shouldnt freak out or maybe I should lower my alk 2 part very slightly to counter the rise in all while slowly dose nitrate to get to 2-4ppm

 

[LARedstickreefer]

According to that link, you need to dose 50ppm nitrate to go up 2.3dkh. How much nitrate have you dosed?

 

[Michael Gray]

@LARedstickreefer
if i had to estimate for the last 6-7 days or so. ive dosed 6ml which i mixed to be about. per calculator is only .88ppm for 6ml.

so not much. plus my feeding.