DIY Phosphate Dosing Recipe

[TwelveL16]

Has the tank gotten warmer w the season recently?

This is tough, you will get all kinds of info for this.

Me? I'd keep dosing the phos knowing the corals get something. Eventually it will test. Coral health looks good still ... Am I missing anything there?
How's your nitrates level?
Are you dosing any bacteria or carbon for bacteria?

No, temp has remained the same nitrates are 10. I’ve lost 2 sps frags in the past week. I was adding “seachems pristine” a couple times a couple weeks ago as I felt like my water just wasn’t very clear but that’s the only thing I’ve added. Not dosing carbon.

 

[TwelveL16]

Has the tank gotten warmer w the season recently?

This is tough, you will get all kinds of info for this.

Me? I'd keep dosing the phos knowing the corals get something. Eventually it will test. Coral health looks good still ... Am I missing anything there?
How's your nitrates level?
Are you dosing any bacteria or carbon for bacteria?

I guess I should add, the whiter rocks in the photo are a new addition due to a tank upgrade. Everything else is from the old tank. I assume that’s what is sucking up all the phos.

 

[Featherweight]

Could be, I used some Marco w my seeded live rock and had to basically bolus dosed phos for a week until it would read. Now I only need 7 ml stock solution per day in about 110gallons to maintain my phos above .08 to .2 (usually sits around 0.1 now

 

[Miami Reef]

I intend to get the items you suggested but this is what I have on hand so might as well use it. I’ll add the 85ML today or whatever I have left and order the items you suggested. Feels wrong adding this much but I trust ya lol.

Thank you for your help.

That’s fine. I would also finish what’s remaining. It seems like a lot of volume, but their product is very dilute.

 

[Mschmidt]

Would it be in any way practical to soak a few rocks in a heave solution till they soak the po4 up then put them in the tank? My right is that would allow for a more gradual leaching into the water column than a bolus.

I would mention this is to fight dinos, so I'm less concerned with maintaining appropriate levels as I am with raising to help the fight.

 

[Miami Reef]

Presoaking them would prevent the display PO₄ from dropping, if that’s the goal. However, you can always just dose more in the DT.

To pre-saturate: submerge the rocks in seawater with circulation. Ensure the bulk water maintains similar levels for about two days prior to adding them.

 

[KStatefan]

Would it be in any way practical to soak a few rocks in a heave solution till they soak the po4 up then put them in the tank? My right is that would allow for a more gradual leaching into the water column than a bolus.

I would mention this is to fight dinos, so I'm less concerned with maintaining appropriate levels as I am with raising to help the fight.

I think that it would be hard to calculate how much rock at what ppm and for how long would give you the results you wanted. Why not dose more often why bolus?

 

[Mschmidt]

Presoaking them would prevent the display PO₄ from dropping, if that’s the goal. However, you can always just dose more in the DT.

To pre-saturate: submerge the rocks in seawater with circulation. Ensure the bulk water maintains similar levels for about two days prior to adding them.

The goal would be to cut off some of the decrease from it binding when I dose, and help the rest of the media bind as well.

I think that it would be hard to calculate how much rock at what ppm and for how long would give you the results you wanted. Why not dose more often why bolus?

If I cared about the exact number, it would be a bad method. But at this point, for fighting dinos, I just want greater than 0. I have a lot of rock and sand to bind (and other export methods that can't be stopped) so keeping measurable po4 is hard.

If I had a doser or I could add it to my 2 part, then more frequently would work. But I have no other doser and haven't found out if it could be added to the 2 part. It's in the ATO now, but that relies on EVAP to dose; it's been wet and cool lately.

Why bolus, cuz that's what I got time for.

 

[Miami Reef]

I’m a big fan of bolus dosing.

The scenario is too common: people have 0.00 ppm PO4. They add 0.01 or 0.02 ppm per day, but it instantly drops, so they’d have to test daily to check. This process can go on for weeks. It’s not unusual to hear people testing PO₄ daily during this process.


It’s much easier to add a large amount like 0.10 - 0.20 ppm PO₄. You get the rocks saturated quicker, and you’d more than likely still have a detectable level after a week. You can decide to add more or not during that next test.


My goal is to remove P limitations as soon as possible so corals can improve and dinos can fade. I don’t have the patience to wait around and excessively test, and I haven’t had any issues with my method.

 

[Randy Holmes-Farley]

I agree that controlling a dose that way would be tricky, but it’s a fine thing to do.

That said, I’ve not seen evidence that bolus dosing of phosphate when needed is any concern.

 

[Mschmidt]

I saw it drop from .6 to 0 ina few days, it was probably binding, but could be another method of depletion. As long as there's no to little danger with a heavy dose, I might do that.
I'm running carbon for any toxins in the dinos, a skimmer, and a small amount of macro algae (and mangroves, but I'd bet they're not drinking that heavily).

Otherwise between Rick and sand, I probably have 75# of media in a 40 gallon tank. I should probably pull some sand out...

 

[Ziggy17]

Edit.

Posted in the wrong thread.

 

[rishma]

I need to order a new bottle from loudwolf. Is there any benefit to mono, di, or tri? I recognize they are largely interchangeable. The only difference I can see pH of aqueous solution. I previously used TSP which is quite basic, but dose is too small to matter in a tank.

Any rationale to choose one? Price is the same.

 

[Randy Holmes-Farley]

At the doses used, the pH differences are minor and unimportant. Mono has the most phosphate per gram, but again the difference is small.

 

[Paul Corral]

saving this for later.

 

[MYACROS.WONTGROW.504]

Sometimes phosphate can be so stubbornly low that the only way to meaningfully raise it is by directly dosing phosphate.

When you feed foods, you’re adding nitrogen, carbon, and loads of organics. This effect is compounded if you’re trying to offset rocks that initially work against you by binding up most of the PO₄ until a higher equilibrium is met. It’s much cleaner and more cost-effective to purchase pure sodium phosphate online than to use hobby-grade products with unknown purities and byproducts.


You can mix sodium phosphate with nitrate, ammonium, or even add it to an ATO; however, phosphate should not be mixed with limewater (kalkwasser), as it will completely precipitate as calcium phosphate. You may need to dose more than expected, as calcareous sand and rock can bind much of it, especially when phosphate levels are near zero.


Sodium Phosphate Dibasic (Na₂HPO₄) Recipe:

Sodium phosphate dibasic (Na₂HPO₄) is 66.9% phosphate (PO₄³⁻) by weight.

0.02 ppm in 100 L = 2 mg of PO₄³⁻.
2 ÷ 0.669 = 2.99 mg of Na₂HPO₄.

Dissolve 3 g of Sodium Phosphate Dibasic (Na₂HPO₄) in 1 L of freshwater.

Dose 1 mL per 100 L to raise PO₄ by 0.02 ppm.

Note: Monobasic, dibasic, and tribasic forms are interchangeable. Concentrations vary slightly but are functionally similar when accounting for rock adsorption.

If calculators are easier, you can follow this link. Select “potassium phosphate.”

James' Planted Tank - Dosing Calculator

I use kalk in Ato and I just dosed my P04 will it still precipitate out or that’s only when added to Ato?

 

[Miami Reef]

I use kalk in Ato and I just dosed my P04 will it still precipitate out or that’s only when added to Ato?

Correct. It’s only a problem when are both mixed in the same container. Dosing them separately does not pose the same issue.

 

[08TRDOFFROAD]

If I have been dosing 7 ml
of Neophos daily to maintain my phosphate levels in my 75 gal system. How many ml of this diy solution should I dose to equal my previous dose of neophos? Just want to check my math...

Neophos 1 ml raises phosphate .016 in my system (1.2/75=.016). I'm dosing 7 ml per day, (.016x7) so dosing ~.12 ppm per day.

DIY solution 1 ml raises phosphates .02 per 100 L. My system is slightly under 300 L. So 3 ml will add .02 phosphate. So need 6x that to equal my .12 dose per day of neophos. So I should dose 18 ml of the diy solution.

Is that correct?

I am using the loudwolf sodium phosphate dibasic powder.

 

[Miami Reef]

So I should dose 18 ml of the diy solution.

Yes.

 

[Reefer1978]

@Miami Reef do you know if there's any place to get this stuff in person so I don't have to wait for shipping?