Another post about Nitrates and Phosphates

[Pico_Reefs]

I'll start this with my question(s):
Should I start dosing PO4?
Should I start carbon dosing?
Should I do both?
Should I start a Refugium?


My tank overall looks pretty good, but I want to achieve a little more balance. I would say the tank is on the heavier side of stocking both livestock and corals.

-Nitrates are at 20ish (might be 14-15 post weekly water change and back up to 20 by the following water change)
It's been doing this rather consistently for a while. I started running a skimmer about a month ago. I've been what I thought was rather aggressive with it by running pretty wet (the cup is full by the next water change), but it's made 0 change in nitrates.

For the past few months, my Po4 has been stuck at 0. Sometimes, it will rise to .02, but never for long.

Tank: 15g Innovative Marine
Light Ai Prime
Filtration: Rollermat +bubble magus skimmer + bio media

Salinity 1.025
Alk: 9.1
Cal:470
Mag:1500
P04: 0
Nitrate: 20

 

[Randy Holmes-Farley Verified Community Expert]

In this situation, I’d dose food grade sodium phosphate until it comes in scale.

 

[Pico_Reefs]

In this situation, I’d dose food grade sodium phosphate until it comes in scale.

Should I turn off my skimmer or maybe reduce its aggressiveness and run it a bit dryer?

I have some NeoPhos. I added .5ml yesterday waited for 24hr and it didn't budge.

 

[Randy Holmes-Farley Verified Community Expert]

Should I turn off my skimmer or maybe reduce its aggressiveness and run it a bit dryer?

I have some NeoPhos. I added .5ml yesterday waited for 24hr and it didn't budge.

Neophos is weak, expensive, and of unknown purity, hence my suggestion. It is probably fine, but you’ll need to dose more.

I personally would not reduce skimming or feed more with nitrate already at 20 ppm.

 

[Pod_01]

Just a suggestion, I would remove the roller mat and bio media.

That may help with your nitrates and PO4.
Or not use them for month or two and see how things develop.

For example I only use skimmer and GAC and my Nitrate are around 1-3 ppm or less.

 

[Salty_Northerner]

Should I turn off my skimmer or maybe reduce its aggressiveness and run it a bit dryer?

I have some NeoPhos. I added .5ml yesterday waited for 24hr and it didn't budge.

Like randy said neophos is weak and you better double up the dose and monitor. I had the same issue, and found that double the dose would actually do something, but I've gone down a different path for low po4 and has been working great.

 

[Pico_Reefs]

Neophos is weak, expensive, and of unknown purity, hence my suggestion. It is probably fine, but you’ll need to dose more.

I personally would not reduce skimming or feed more with nitrate already at 20 ppm

You said, "I personally would not reduce skimming or feed more with nitrate already at 20 ppm," as if it were a problem. I understand that 2-5 ppm is considered optimal, but we have all seen tanks thriving with 20 ppm and much higher.

Is your reason for concern because the difference between the two is so significant ( I know a little about ratios)? Is there a point where you would reduce skimming, excluding a drop in nitrates (if PO4 increases to x)?

 

[Randy Holmes-Farley Verified Community Expert]

You said, "I personally would not reduce skimming or feed more with nitrate already at 20 ppm," as if it were a problem. I understand that 2-5 ppm is considered optimal, but we have all seen tanks thriving with 20 ppm and much higher.

Is your reason for concern because the difference between the two is so significant ( I know a little about ratios)? Is there a point where you would reduce skimming, excluding a drop in nitrates (if PO4 increases to x)?

20 ppm is likely not a problem, but you might hit 100 ppm or more if you try to bring up phosphate using a method that boosts both N and P. Those include feeding more or using less balanced export like reduced skimming.