Help me bring my phosphate up

Hnguyen85

New member
Hi all, I seem to be having a hard time with my phosphate in that it's too low. Undetectable to be exact. I'm testing with my Hanna low range phosphate check as well as the Hanna phosphorus ultra low range and both are reading zero.

Yesterday I decided to try adding some Neo-Phos to help bring it up. I only dosed half the recommended dosage for my tank size, waited 24 hours to test and still zero. Tonight, I dosed again but this time the recommended dosage and will test again tomorrow.

Can anyone explain to me by my nitrates are at 12 ppm but phosphate is reading zero?

I also decided to check if my hanna check was working properly so I added a few drops of neo-phos to my sample water and that shot the numbers way up. So I assume something in my tank is reducing all my phosphates. I'm trying to keep phosphate around .08ppm.


Cal = 450
Alk = 11.5 dkh
Mag = 1300
Ammonia = 0
Nitrite = 0
Nitrate = 12ppm
Salinity = 1.025

Thanks
 
There are a lot of unknown variables here - are you skimming, carbon dosing, GFO, carbon reactor, do you add food, chaeto?
Cheers! Mark
 
I'm skimming with a Nyos 160, running BRS ROX carbon in a vertex media reactor and currently dosing 4ml of Red Sea Nopox daily. System is a Red Sea Reefer 525XL. Tank has 7 fish and over a doze corals, some large. Feeding twice daily with pellets and once daily with frozen foods.
 
double your feedings, no need to waste money on phosphate in a bottle

Well.. that will just double your food costs and put more than just phosphate into the system so phosphate dosing can be a much smarter move..
Dosing is also much easier to regulate/adjust/dial in...
 
I personally would just stop skimming for a bit(maybe try on for a few hours a day instead of 24/7), and increase the PO4 additions.



With carbon dosing your removing PO4 and NO3. Since you have fairly high nitrates and 0 phosphates, your phosphate limited, meaning that the nopox cannot feed the bacteria to reduce no3 until you add in some po4. it might take quite a bit to fill up the voids in po4. Just keep adding and testing till your at a comfortable level.



I had the same issue but with no3, not po4. Started nitrate dosing(stump remover) and my no3 is now 2ppm(up from 0), and my po4 is down to .031(from .126).
 
Do you have any algae of any kind? Do you need to scrape algae of the glass?

If you have algae of any kind, anywhere inside the tank, you have enough P. It means P is consumed very fast and doesn't stay free in water for long. I had ULNT with truly zero phosphate. There was no algae, I could go without cleaning the glass for weeks and not even had coraline algae.


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Do you have any algae of any kind? Do you need to scrape algae of the glass?

If you have algae of any kind, anywhere inside the tank, you have enough P. It means P is consumed very fast and doesn't stay free in water for long. I had ULNT with truly zero phosphate. There was no algae, I could go without cleaning the glass for weeks and not even had coraline algae.


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I don't have any algae in my tank other than diatom. At least that's what I believe it to be, it's a brown rust that coats everything. I never had a diatom out break during my cycle but it decides to start now after having the tank run for 3 months.
 
I don't have any algae in my tank other than diatom. At least that's what I believe it to be, it's a brown rust that coats everything. I never had a diatom out break during my cycle but it decides to start now after having the tank run for 3 months.



That means you probably have enough phosphate.


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Balancing nutrients in a young tank is difficult. It may be best to just let the tank stabilize some before starting to mess around with these parameters. There is nothing wrong with 12 ppm nitrate and undetectable phosphate for a young tank. The diatom phase will pass. You may (will) get some algae too... hair, turf, and or Cyano. Get an Urchin and some other clean up specimens to control it until it passes.

If phosphate is truly 0, you may not be doing any good using the Nopox. Weaning the tank off of it might not change anything.

If you decide you need to raise phosphate, so the Nopox might have some impact, potassium phosphate from plant fertilizer will work, but you can overdose it quite quickly. You can also feed some really cheap flake food for a while.
 
But if it's undetectable than wouldn't that mean I don't have enough? Not trying to question you, I'm just trying to get a grip on this and understand it.

Nope, it just means it is being consumed. If you didnt have enough P for corals, you would have no algae. Corals can live in much lower phosphate levels than algae (with some exceptions like bubble algae). Since you have diatoms covering everywhere, there is plenty of phosphate. If you add more phosphate you will likely get more algae (as right now it is limiting their growth) until nitrate (or silica for diatoms) become limting . Keep in mind hobby grade kits only measure orthophosphate, there are many other forms of phosphate like polymeric and organic phosphates.
 
My guess is your NO3 is 12 bc a combo if factors:
1) you're feeding the fish more than your skimmer can keep up with.
2) you're not doing enough of a % of WC
3) you're not doing enough WC frequencies

Maybe try to feed less , do more WCs
 
My guess is you are feeding the fish more than your skimmer can keep up with......or you're not doing enough of a % of WC and/or not doing enough WC frequencies
I'm running a nyos 160 in a reefer 525xl, it's well rated for this size tank. Also doing weekly 20 gallon WC.

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pfft.. so new...I wouldn't suggest doing anything at this point as far as phosphate dosing goes.. At this point is highly likely that the only thing phosphate dosing will do at this time is increase nuisance algae issues..

When you hit the 1 year mark check it again and we can go from there..
 
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