Dose Po4 in 5 month old tank

[Aquajan]

Hi all,

I have just added the first corals in my tank 2 weeks ago.
So at that point I also started dosing kalkwasser to keep it all stable.
But since I dose kalk my phosphate is 0 and after dose it up with po4+ to 0.02 it is 0 again after a day.
Befor I dosed kalk my Po4 was 0.05 to 0.03.
I dose a saturated solution with a dosing pump so it clearly precipitates out the Po4.

So I'm thinking about putting the po4+ bottle on a doser and dose it to 0.01 Po4 just after the lights go on and half way the light cycle again 0.01.
But... As it is a new tank I wonder if this is wise to do at this point?

I don't want to create a big algae bloom or other problems.

The tank is 75 gallon barebottom.
Rock is 20 Kg Aquaforest synthetic rock.

Kh =8.12 hanna
Ca=430 RS pro
Mg=1350 Aquaforest
No3=8 RS pro
Po4=0. 00 hanna
Salinity=1.025
Temp=25

Filtration:
Skimmer
Rollermat
10%wc a week
Marine pure blok
Marine pure balls

I have a yellow tang and 5 small fish and some hermids.
I feed 2x pellets with an autofeeder and 1x half a cube of frozen food.
And nori every day or 3 times a week depending on the algae in tank.
The corals I added are 6x sps frag and 3x lps frag.

With regards

Gertjan

 

[Spare time]

Have you considered using coral food instead to get it up? I know you have less control that way but I feel like it's nice to have it be used as food and then what's left can remain as phosphate.

 

[Aquajan]

Yes I have considered,

I would rather feed more but my nitrate level is at 8ppm now witch is already higher than I like it to be.
Nitrates are creeping up since I added the last to fishes and I have started to dose nopox 5 days ago.
Nopox also reduces Po4 in some degree so that's another reason to dose Po4.

The only alternative for dosing Po4 would be a food source witch has alot more Po4 than No3..
I have not found any food witch has that composition.

And finally feeding is indeed less controlled than dosing Po4 and it would seem to me that stability is very important at this early stage.

Of all the tings I have read and heard it is best to keep nutrients low and stable in the first year and after a tank matures low nutrients matters less.
So I aim for a No3 off 2-5 and a Po4 of 0.01-0.03.
I think that is a nice base to begin with.

 

[Spare time]

Yes I have considered,

I would rather feed more but my nitrate level is at 8ppm now witch is already higher than I like it to be.
Nitrates are creeping up since I added the last to fishes and I have started to dose nopox 5 days ago.
Nopox also reduces Po4 in some degree so that's another reason to dose Po4.

The only alternative for dosing Po4 would be a food source witch has alot more Po4 than No3..
I have not found any food witch has that composition.

And finally feeding is indeed less controlled than dosing Po4 and it would seem to me that stability is very important at this early stage.

Of all the tings I have read and heard it is best to keep nutrients low and stable in the first year and after a tank matures low nutrients matters less.
So I aim for a No3 off 2-5 and a Po4 of 0.01-0.03.
I think that is a nice base to begin with.

8 ppm nitrate is near perfect sonic wouldnt worry about increasing it that much especially if you use nopox. I would just dose phosphate manually and use a hannah ulr checker. I think that you will eventually not need the dose for phosphate. Red sea recommends using their reef energy with nopox to keep some phosphate and nitrate in the tank when running nopox and I think a coral food may be able to work. Usually nopox in my experience causes really low nitrates even with heavy feeding so again I wouldnt worry about that.


Again in my opinion I wouldnt spend money on the doser as I dont think the phosphates will be an issue forever. Nopox never seems to drag phosphates to 0 in an established system from my personal experience.

 

[LARedstickreefer]

Feed some pellets and reef roids. That’ll get your phosphate up. Be careful though, it will get up there!

Having said that, I think that you are doing way too much stuff in a 5 month old tank that was started with dry rocks.

 

[Aquajan]

I already have a doser for dosing nopox and have 3 heads to spare so auto dosing would seem more stable to me..
I ofcourse will monitor Po4 closely when I do this.
And for nopox I only dose only 2 ml a day on 350l as I don't want to drag nitrates down mutch and I want to start it very slow.

But as LARedstickreefer said it's mutch to do on a 5 month system.
That's why I started with kalk becous it is simple and stable.

But what would be a good alternative?

Continue with kalk, stop nopox and just adjust feeding to No3 so it won't get higher than 10 and let the Po4 for what it is?

I heard Po4 at absolute 0 is likely to cause dinos/cyano..

Or stop kalkwasser and do 2part as I got everything for it.. Only have to fill the containers and program the doser.

I do like kalk just becous of its simplicity and the higher ph and low cost..

 

[LC8Sumi]

Watch this before dosing po4 (because sometimes it is chemistry that consumes it)

 

[Randy Holmes-Farley]

Watch this before dosing po4 (because sometimes it is chemistry that consumes it)

why watch that first? I have nothing against the parts I watched, but I don’t see how the particular sinks for phosphate in any given tank bears on whether it is useful to dose more phosphate to maintain desirable levels.

 

[X-37B]

If you have algae on your glass every couple of days you have phosphate and I would not worry about the 0 reading.. Your hanna meter might read 0 but it could be .04 due to accuracy of the unit. Feed more is good advice!

 

[LC8Sumi]

why watch that first? I have nothing against the parts I watched, but I don’t see how the particular sinks for phosphate in any given tank bears on whether it is useful to dose more phosphate to maintain desirable levels.

My humble opinion - I’m not an expert so I can be totally wrong - is that dosing PO4 is tricky, because it’s not just corals (and other lifeforms) that are taking it up, but it seems like it could also bind to inorganic molecules. Perhaps this happens only in small amounts and have no effect whatsoever, but maybe it could “mess” with available CO3 levels as well and maybe test readouts - I mean that the test is measuring it, but it’s perhaps bound to CO3, so both not available for corals. I’ve experienced erlier a strange thing with PO4. I’ve dosed it and dosed it, and the level didn’t rise linearly. The system almost acted like something is buffering it. Then one day (after the same as usual daily dose), it went boom exponentially. This might be totally wrong, and your knowledge and opinion ofcourse stands above mine, no question asked!

 

[Randy Holmes-Farley]

My humble opinion - I’m not an expert so I can be totally wrong - is that dosing PO4 is tricky, because it’s not just corals (and other lifeforms) that are taking it up, but it seems like it could also bind to inorganic molecules. Perhaps this happens only in small amounts and have no effect whatsoever, but maybe it could “mess” with available CO3 levels as well and maybe test readouts - I mean that the test is measuring it, but it’s perhaps bound to CO3, so both not available for corals. I’ve experienced erlier a strange thing with PO4. I’ve dosed it and dosed it, and the level didn’t rise linearly. The system almost acted like something is buffering it. Then one day (after the same as usual daily dose), it went boom exponentially. This might be totally wrong, and your knowledge and opinion ofcourse stands above mine, no question asked!

Yes, it is buffered hugely by binding to rock and sand surfaces. Far more, in most cases, than is actually in the water. It happens to a huge extent. But it is not to be feared. It just makes rises and falls of phosphate much slower than expected based on simple calculations.

 

[Aquajan]

Yes I have heard of that happening with more reefers.
New rocks and sand made of aragonite would be a Po4 sponge as I have heard/read and after a while a limit is reached and than Po4 can rise very fast and algae grows from the Po4 straight out of the rock witch makes it hard to get rid of.

That is mainly why I asked if to dose Po4 to begin with as I don't want that to happen.

The tank is new and there are lots of prosesses that can use up the Po4.
Although I think the kalkwasser is the blame.. It could also be the rock or the corals but....
When I first dosed the kalk next to the Skimmer it overcooked.
And saturated kalkwasser can
precipitate po4 to calcium phosfate witch can be skimmed out.
And as I said before the Po4 dropped to 0 after I started dosing kalk.
I have dosed some Po4 and measured 30 mins later and it had risen exactly to the amount I had dosed (0.03) and 24h later it was gone.
The skimmate has become a bit lighter too and a bit more (befor dosing nopox) ofcourse it now further increased becouse of nopox.

 

[Aquajan]

I use only synthetic rock and only a tupperware box with Fiji sand so I dont know if the rocks I have take up mutch Po4.

 

[Randy Holmes-Farley]

Yes I have heard of that happening with more reefers.
New rocks and sand made of aragonite would be a Po4 sponge as I have heard/read and after a while a limit is reached and than Po4 can rise very fast and algae grows from the Po4 straight out of the rock witch makes it hard to get rid of.

That is mainly why I asked if to dose Po4 to begin with as I don't want that to happen.

The tank is new and there are lots of prosesses that can use up the Po4.
Although I think the kalkwasser is the blame.. It could also be the rock or the corals but....
When I first dosed the kalk next to the Skimmer it overcooked.
And saturated kalkwasser can
precipitate po4 to calcium phosfate witch can be skimmed out.
And as I said before the Po4 dropped to 0 after I started dosing kalk.
I have dosed some Po4 and measured 30 mins later and it had risen exactly to the amount I had dosed (0.03) and 24h later it was gone.
The skimmate has become a bit lighter too and a bit more (befor dosing nopox) ofcourse it now further increased becouse of nopox.

It makes no difference if you dose phosphate or if you feed more. if the goal is to, say, maintain 0.01 ppm phosphate, a fixed amount will bind to the rock.

 

[Randy Holmes-Farley]

I use only synthetic rock and only a tupperware box with Fiji sand so I dont know if the rocks I have take up mutch Po4.

All calcium carbonate rocks will bind phosphate. The more exposed surface area, the more they bind.

 

[Aquajan]

If you have algae on your glass every couple of days you have phosphate and I would not worry about the 0 reading.. Your hanna meter might read 0 but it could be .04 due to accuracy of the unit. Feed more is good advice!

I've monitored the algae and after 5 days without cleaning the glass it starts to limit the sight.
So I asumme the Po4 is consumed so fast that I get a 0.00 reading.

So as the tank is new I think it's best to not dose it for at least the comming months.
LPS seems fine and that's a good indicator for Po4 to issnt it?

 

[Spare time]

I've monitored the algae and after 5 days without cleaning the glass it starts to limit the sight.
So I asumme the Po4 is consumed so fast that I get a 0.00 reading.

So as the tank is new I think it's best to not dose it for at least the comming months.
LPS seems fine and that's a good indicator for Po4 to issnt it?

Tbh as long as they look good and you are for sure providing them with a constant supply of food I wouldnt be too worried. I doubt it's truly zero if you are seeing algae pop up. If you have zero algae and it says zero then I'd be worried