10ppm phosphate

MiddleEyeNoir · Jul 17, 2025

I have a relatively new system (~6 mo old, but crashed and restarted about 3mo ago for unknown reasons) where the hanna checker always went out of range for phosphates (> 0.9) for the last few months. I realized that I could just dilute the solution and just multiply, and using a red sea test kit, it placed my Phosphate at about 10ppm. This number shocked me, since according to common knowledge, this tank should've been long dead by now, however the corals don't seem to be super bothered by it.

Doing well:
Acan lords are growing like crazy
Discosoma get bigger all the time
GSP growing, but slowly

Surviving - Look happy but aren't growing:
Torches
Toadstool leather
Kenya tree
Goni
Monti cap
NPS sea fan

Slowly Shrinking:
Zoa
Clove

Nitrates are usually bottomed out, so I dose nitrates (Aquaforest) and amino acids (Red sea, tropic marin, etc). I run a refugium and nopox to help with the phosphate. I'm considering GFO but I'm afraid since its been a high phosphate system for so long, it might actually cause more harm than good.

7.8-8.0 pH
Alk 9-11 dKH

Should I be worried about an impending crash?

Kingsley_Reef · Jul 17, 2025

IMO
Refugium and NOpox is the cause of your bottomed out nitrates and does nothing for phosphates

GFO is safe just start small

Are you running a skimmer at all?

MiddleEyeNoir · Jul 17, 2025

I was under the impression nopox reduced both nitrates and phosphate at a 20:1 ratio (hence dosing nitrate with nopox). You think that's not the case? I also feel like my chaeto isn't growing super fast. I trim it every ~2 weeks (this is a 50L system).

I'll give GFO a try.

Running a tunze 9001DC skimmer. It is very wet. The skimmer is placed after a Redsea nanomat roller.

FernBluffReef · Jul 17, 2025

MiddleEyeNoir said:
I was under the impression nopox reduced both nitrates and phosphate at a 20:1 ratio (hence dosing nitrate with nopox). You think that's not the case? I also feel like my chaeto isn't growing super fast. I trim it every ~2 weeks (this is a 50L system).

I'll give GFO a try.

Running a tunze 9001DC skimmer. It is very wet. The skimmer is placed after a Redsea nanomat roller.

As I understand it. NoPox takes time. Nitrate reduction first and then after a much longer time some phosphate reduction. Some being the operative word. They say ‘in Ratio’ and the percentage of phosphate is pretty low. I never heard 20:1. I always thought it was closer to 100:1. Regardless, if you don’t have any Nitrates……

I personally have run NoPox - tried for about a year - any more its essentially been off for months as corals and phyto take care of my Nitrates I guess, i have to dose a substantial amount of Nitrate daily. I’m summary agree others…. If you don’t have any nitrates dosing NoPox is futile.

I’ve moved onto dosing Lanthinum (recent), only because I can dose it. I don’t want to deal with reactors. My CO2 scrubber is enough to worry about media. Which ever way you go, it will take time to reduce your phosphates

Kingsley_Reef · Jul 17, 2025

It does but I guess what I’m trying to say is for such a young system nopox and cheato is stripping your tank I would pull both off for now until the system becomes more mature you should be able to manage your nitrate phosphate with good husbandry (replacing filters) skimming and water changes small amounts of gfo biweekly will also help get closer to your target numbers