Dosing phosphates

[Stuckita]

My phosphates are undetectable. All tests showing 0 on a Hanna checker. Nitrates are 25-30.

I’ve picked up some aqua forest p04+ and will begin dosing tonight. It says 1ml per 100L to bring it up 0.01, and max daily dose of 1ml per 100L. Is it okay to go slightly above that? Say 2-3x on initial dose?

 

[gbroadbridge]

My phosphates are undetectable. All tests showing 0 on a Hanna checker. Nitrates are 25-30.

I’ve picked up some aqua forest p04+ and will begin dosing tonight. It says 1ml per 100L to bring it up 0.01, and max daily dose of 1ml per 100L. Is it okay to go slightly above that? Say 2-3x on initial dose?

The reason they would say that is so that you don't accidentally overdose and create an algae paradise.

If you're certain of the test result, there is no harm in dosing more as the phosphate is going to be taken up by carbonate structures in the tank.

You will probably find that even if you dose 3ml per 100l, after 24 hours the reading will again be zero, and you will need to dose more.

 

[Stuckita]

The reason they would say that is so that you don't accidentally overdose and create an algae paradise.

If you're certain of the test result, there is no harm in dosing more as the phosphate is going to be taken up by carbonate structures in the tank.

You will probably find that even if you dose 3ml per 100l, after 24 hours the reading will again be zero, and you will need to dose more.

Yes this is what I was worried of, I was hoping to boost it and then maintain at 1ml/100L until I can get things stable again.

I was attempting to raise via over feeding but this was throwing my nitrates even higher. Going to do another water change and begin the phosphate dosing.

How often should I be checking phosphates after dosing?

 

[gbroadbridge]

Yes this is what I was worried of, I was hoping to boost it and then maintain at 1ml/100L until I can get things stable again.

I was attempting to raise via over feeding but this was throwing my nitrates even higher. Going to do another water change and begin the phosphate dosing.

How often should I be checking phosphates after dosing?

I'd check the next day to see where you are.

Once you get a reading slow down the dosing because it takes just as long to take it out as it does to put it in..
You really don't want to end up over 0.05ppm

 

[Stuckita]

I'd check the next day to see where you are.

Once you get a reading slow down the dosing because it takes just as long to take it out as it does to put it in..
You really don't want to end up over 0.05ppm

Perfect sounds like a plan. I’ll mess it up, but a plan none the less.

 

[gbroadbridge]

Perfect sounds like a plan. I’ll mess it up, but a plan none the less.

If it's a newish tank it will take more than you expect to show a reading as it will be absorbed into the rocks and sand. Don't be surprised if it takes quite a lot of dosing.

 

[Randy Holmes-Farley Verified Community Expert]

My recommendation for the first couple of doses is 0.02 to 0.03 ppm. Most folks wont detect any of that 24 h later. Then ramp up the dose as needed so you detect what you want 24 h later. .

I also recommend food grade sodium phosphate as it is cheap and guaranteed purity.

 

[Stuckita]

My recommendation for the first couple of doses is 0.02 to 0.03 ppm. Most folks wont detect any of that 24 h later. Then ramp up the dose as needed so you detect what you want 24 h later. .

I also recommend food grade sodium phosphate as it is cheap and guaranteed purity.

Good to know! I bought the reef stuff this round but in the future I’ll look for cheaper options.

 

[gregrock68]

My recommendation for the first couple of doses is 0.02 to 0.03 ppm. Most folks wont detect any of that 24 h later. Then ramp up the dose as needed so you detect what you want 24 h later. .

I also recommend food grade sodium phosphate as it is cheap and guaranteed purity.

Glad I found this link with your recommendation @RandyHolmes-Farley. I'm looking on Amazon for the food grade sodium phosphate and there are many different types. I see mono basic sodium phosphate, bi - sodium phosphate , trisodium phosphate, sodium dibasic phosphate. So many options. I presume the mono basic is what you are recommending?

 

[Randy Holmes-Farley Verified Community Expert]

Glad I found this link with your recommendation @RandyHolmes-Farley. I'm looking on Amazon for the food grade sodium phosphate and there are many different types. I see mono basic sodium phosphate, bi - sodium phosphate , trisodium phosphate, sodium dibasic phosphate. So many options. I presume the mono basic is what you are recommending?

All except sodium tripolyphosphate are fine. The difference is a very tiny pH and alk difference.

 

[gregrock68]

Glad I found this link with your recommendation @RandyHolmes-Farley. I'm looking on Amazon for the food grade sodium phosphate and there are many different types. I see mono basic sodium phosphate, bi - sodium phosphate , trisodium phosphate, sodium dibasic phosphate. So many options. I presume the mono basic is what you are recommending?

All except sodium tripolyphosphate are fine. The difference is a very tiny pH and alk difference.

Thank you, I appreciate your guidance

 

[Randy Holmes-Farley Verified Community Expert]

You’re welcome

Happy Reefing!

 

[gregrock68]

You’re welcome

Happy Reefing!

One more question. I presume I should mix this with my RO water? If that's the case is there a suggestion on the amount of powder I should use to create my batch for dosing, or do I just follow the directions? I figured the directions wouldn't be applicable since this is typically used for food applications

 

[Randy Holmes-Farley Verified Community Expert]

One more question. I presume I should mix this with my RO water? If that's the case is there a suggestion on the amount of powder I should use to create my batch for dosing, or do I just follow the directions? I figured the directions wouldn't be applicable since this is typically used for food applications

Yes, dissolve in ro water. As long as it dissolves, the concentration does not matter. This calculator and the entry for phosphate from potassium phosphate is close enough:

http://www.theplantedtank.co.uk/calculator.htm

 

[gregrock68]

One more question. I presume I should mix this with my RO water? If that's the case is there a suggestion on the amount of powder I should use to create my batch for dosing, or do I just follow the directions? I figured the directions wouldn't be applicable since this is typically used for food applications

Yes, dissolve in ro water. As long as it dissolves, the concentration does not matter. This calculator and the entry for phosphate from potassium phosphate is close enough:

http://www.theplantedtank.co.uk/calculator.htm

THANK YOU! I just tried the calculator and this is perfect! I wasn't aware I could dose an off the shelf product! I have been burning through my regular brand "purchased product" at a high rate trying to maintain phosphate, this is a big cost savings. THANK YOU FOR YOUR ADVICE!

 

[Randy Holmes-Farley Verified Community Expert]

THANK YOU! I just tried the calculator and this is perfect! I wasn't aware I could dose an off the shelf product! I have been burning through my regular brand "purchased product" at a high rate trying to maintain phosphate, this is a big cost savings. THANK YOU FOR YOUR ADVICE!

You’re welcome.

Happy Reefing! :)

 

[seahuy]

GO VERY SLOW with p04 dosing

try to knoww hat your tank is consuming -- if you already have some historical data, try to figure out the consumption rate of p04 per day. Then start with that amt to dose and like randy said, wait about 1-2 days before uping the dose slightly like up it by 25%

 

[seahuy]

btw, if you ever accidently dosed too much and need to bring p04 down -- go very slow as well.

Use gfo or phosgaurd but very little and only filter it through a small portion of your return. I use something like a tea bag and let it hang in the sump in some flowing water. It will strip away p04 slowly that way

 

[gregrock68]

GO VERY SLOW with p04 dosing

try to knoww hat your tank is consuming -- if you already have some historical data, try to figure out the consumption rate of p04 per day. Then start with that amt to dose and like randy said, wait about 1-2 days before uping the dose slightly like up it by 25%

Got it! Thank you for the advice! I based on my current consumption, it appears to be around 5ppm/daily according to the Hanna po4 tester. I had definitely noticed some stress in some corals when it bottomed out. Once I started dosing po4 the stressed appearance dissipated

 

[Featherweight]

I just went through this. I bolus dosed at first. Now I dose 6 ml per day in my 100gal cube. Keeps my po4 around .07 to .1 which is the right place to be.

Miami has a sticky on nutrients dosing with mixing formulas. It's great. Look it up.