Low phosphate issues

TLO45 · Apr 29, 2023

I have a larger reef that I’ve been having low phosphate levels.
nitrates have been in the 15-20 range but phosphate is always tough to stay readable. 2 days ago I was at .04, today is zero. I feed heavy ( 5x’s a day with 5 cubes of frozen each feeding) on top of that I usually dose ReefRoids (1-2 teaspoons) 3-4 times a week and Neophos if below .05 I usually test nitrates and phosphate daily simply because levels can bottom out overnight. I also dose 3 liquid coral foods and Acropower at least 3-4 times a week. Perhaps I’m looking too far into this but I certainly don’t want nutrient levels to bottom out. Any suggestions?

taricha · Apr 30, 2023

Some of what you're adding will raise PO4, but some of those are mostly Nitrogen additives, so they might cause your system do draw down PO4 lower.

ksir17 · Apr 30, 2023

I am in the same situation as you, I just picked up NeoPhos to try out but haven't gotten around to use it yet. How has that worked for you? Does it just bring up the phosphates for a little then they drop back close to 0 shortly after?

TLO45 · Apr 30, 2023

ksir17 said:
I am in the same situation as you, I just picked up NeoPhos to try out but haven't gotten around to use it yet. How has that worked for you? Does it just bring up the phosphates for a little then they drop back close to 0 shortly after?

Well in my case it seems to be short lived. However if the above comment is correct then maybe I’m not adding the correct things.
I would like more info on what things are helping and what things are not.

TLO45 · Apr 30, 2023

taricha said:
Some of what you're adding will raise PO4, but some of those are mostly Nitrogen additives, so they might cause your system do draw down PO4 lower.

What do you think is nitrogen and actually lowering phosphate?

Stephen Glover · Apr 30, 2023

Are you getting normal Algae growth? Do the corals look good? If they are don’t worry about the numbers. Sounds like you are introducing plenty of nutrients and you aren’t going to zero out your n03/p04.

EricR · Apr 30, 2023

Some background would help the experts (((not me))) -- tank age and started with dry rock/sand, etc?
*seems fairly common for dry rock to bind/absorb/whatever significant PO4 for quite a bit of time

FWIW, seems fairly common for truly 0 PO4 to promote dino outbreak so maybe just consider that
*maybe none of that applies to you but don't know so just a reminder

TLO45 · Apr 30, 2023

EricR said:
Some background would help the experts (((not me))) -- tank age and started with dry rock/sand, etc?
*seems fairly common for dry rock to bind/absorb/whatever significant PO4 for quite a bit of time

FWIW, seems fairly common for truly 0 PO4 to promote dino outbreak so maybe just consider that

The tank is 3 years old started with Marco rock. About 6 months ago I pulled that and replaced with Caribsea arch rock.
I’ve had Dino’s and ulva algaes in the past but currently things have balanced out.
corals look pretty good and are growing.
zero phosphate makes me nervous. Thus the reason I’m asking.

taricha · Apr 30, 2023

TLO45 said:
dose 3 liquid coral foods and Acropower at least 3-4 times a week.

Acropower is amino acids - Nitrogen and Carbon. I'd expect consumption of that to lower PO4 by some amount. Not sure what your other "liquid coral foods" are. If they are heavy in N or C or both, they might do the same?

EricR · Apr 30, 2023

6 month mark and half dry rock with 0.00 ppm PO4 for a few weeks seemed to be dino outbreak trigger for me, just FYI

TLO45 · Apr 30, 2023

TLO45 · Apr 30, 2023

These are the products I currently dose.

jda · Apr 30, 2023

Are you using a Hannah Ultra Low to measure the po4 levels? If not, then don't sweat this until you get one. Even then 1 to 3 ppb of po4 is more than enough. Your corals can get phosphorous from other sources that you cannot test for and po4 is the least useful form. If your po4 is low, then it is likely getting bound up in the rock and sand.

Edit: you could conisder stopping all of those products and just feed the fish more. Fish will like you better. Corals will be happier with fish waste instead of stuff from a bottle. Everybody is happier except for Brightwell.

TLO45 · Apr 30, 2023

jda said:
Are you using a Hannah Ultra Low to measure the po4 levels? If not, then don't sweat this until you get one. Even then 1 to 3 ppb of po4 is more than enough. Your corals can get phosphorous from other sources that you cannot test for and po4 is the least useful form. If your po4 is low, then it is likely getting bound up in the rock and sand.

Edit: you could conisder stopping all of those products and just feed the fish more. Fish will like you better. Corals will be happier with fish waste instead of stuff from a bottle. Everybody is happier except for Brightwell.

Lol! Good point!

Randy Holmes-Farley · May 1, 2023

If you do choose to dose phosphate, I would avoid Neophos (expensive and of unknown purity).

Better, IMO, is food grade sodium phosphate. Loudwolf is a fine brand.

doubleshot00 · May 1, 2023

Like randy suggested i would dose. In a tank as large as yours (how many gallons?) neo phos is very diluted so it would take a LOT to make any difference. Use what randy suggested.

ptrick21186 · May 1, 2023

5 cubes, 5 times a day, plus all those products? How many gallons is this tank? And how is it stocked? Seems a lot. Perhaps you're not getting accurate tests.....

ptrick21186 · May 1, 2023

I have a 8 month old, 50gal total volume tank with about 7 fish, and handful of different inverts, and 2 small coral frags. I have to dose NeoPhos about a mL per day to keep the phosphates measurable on my Hanna ULR checker.

90's reefer · May 1, 2023

Pics of your system would be nice.
In my 80g I have to dose po4 at 3ml a day to keep the level stable.
I also belong to the feed the fish not the corals.

Rennurdoar · May 1, 2023

Randy Holmes-Farley said:
If you do choose to dose phosphate, I would avoid Neophos (expensive and of unknown purity).

Better, IMO, is food grade sodium phosphate. Loudwolf is a fine brand.

I tried to bring my numbers up with neonitro and neophos. I'm almost positive that the neophos killed almost all my SPS. Things were going great, encrusting and all. Just had 0/0 on No3/Po4. Started dosing 5ml in 100g daily. 2 weeks later everything was gone.

From the onset they all started stress slimming when I used it. Just assumed they were getting used to it. But it just kept going downhill. Stopped dosing Neophos and things are turning around well.

All my test kits would still always show 0 Po4 even. Finally got a hanna ulr and now see my Po4 at .06-.10 usually.

I can't say it for sure was neophos but I'm saying it was the cause in my case lol.