Numerically challenged, please help

[NickHolmes]

Math isn’t a strong point so would appreciate some help. I’m dosing lanthanum and the recommended dosage reduces po4 by 1ppm and the tanks po4 is 0.16. Would that theoretically drop it to 0.06 or should I go back to school?

 

[Lavey29]

Just half dose the recommended amount for your tank volume. .16 phosphate is not bad at all. You would probably find it easier to use a bag of phosguard which walks the phosphate number down slowly.

 

[NickHolmes]

I’m not doing the recommended dosage, just asking if my understanding of the reduction with that dosage is correct

 

[Lavey29]

I’m not doing the recommended dosage, just asking if my understanding of the reduction with that dosage is correct

It depends on your tank volume

http://larryl.emailplus.org/fish/dosing-instructions-phosphate-removers.html

 

[ReefingDreams]

Math isn’t a strong point so would appreciate some help. I’m dosing lanthanum and the recommended dosage reduces po4 by 1ppm and the tanks po4 is 0.16. Would that theoretically drop it to 0.06 or should I go back to school?

You need to lay out tank volume and the instructions for the product/math that got you there. Otherwise we can't check your work.

1ppm should be equivalent to 1.0ppm if you're working in the same units. If so, you would overdose, drive your number to 0.0, and have excess/unbound LC in your water.

 

[NickHolmes]

Sorry I should have said I already worked out the recommended dosage to reduce it by 1ppm for my tank is 20ml. I’m just asking if 1ppm reduction will theoretically reduce my po4 from 0.16 to 0.06.

 

[ReefingDreams]

Sorry I should have said I already worked out the recommended dosage to reduce it by 1ppm for my tank is 20ml. I’m just asking if 1ppm reduction will theoretically reduce my po4 from 0.16 to 0.06.

No. See my prior comment. 1PPM does not equal 0.1PPM.

 

[Lavey29]

No. See my prior comment. 1PPM does not equal 0.1PPM.

Exactly 1ppm is 10x more then .1ppm

 

[Dan_P]

Sorry I should have said I already worked out the recommended dosage to reduce it by 1ppm for my tank is 20ml. I’m just asking if 1ppm reduction will theoretically reduce my po4 from 0.16 to 0.06.

0.16 ppm - 1 ppm = - 0.84 ppm which is likely to be 0 ppm.

 

[NickHolmes]

Hell this is embarrassing. Thank you, just as well I asked first

 

[NickHolmes]

 

[Dan_P]

Hell this is embarrassing. Thank you, just as well I asked first

No problem. We are all challenged about some aspect of this hobby.

 

[Randy Holmes-Farley Verified Community Expert]

I'll give a contrary opinion: I don't think such calculations are useful except to prevent an initial overdose.

Specifically, if you calculated that lanthanum would drop phosphate from 1 ppm to 0.05 ppm, and then monitored the phosphate over the next few days (even with no feeding), it likely will not drop that low, and will rise a long way back toward the 1 ppm due to desorption from rock and sand.

Thus, I'd only use a calculation as a starting dose and then stop calculating and just go by trial and error based on testing.