How to derive how much to dose?

[torque6]

Hi,

I have both sechem phos. Its labelled on the back as

sechem phos
0.3% phosphate = 3000 ppm
0.2% potassium = 2000 ppm

looking at just phospate dosing
250ml = 3000 ppm for 1 litre
so

ppm litre
250ml 3000.00 1
250ml 1500.00 2
250ml 750.00 4
250ml 375.00 8
250ml 187.50 16
250ml 93.75 32
250ml 46.88 64
250ml 23.44 128
250ml 11.72 256
250ml 5.86 512
250ml 2.93 1024
250ml 1.46 2048
250ml 0.73 4096
250ml 0.37 8192
250ml 0.18 16384

though the numbers dont seem right, as fertfriend online calculator had 1ml treating 1 litre of water coming up to 4.7287 PPM, how is this number derived ?

Appreciate some help. thanks.

 

[orion2001]

Hi there,

Did you see this at the Seachem website?

"To target a specific phosphate increase, dose according to the following formula: 0.8vp=m, where v= volume of tank in gallons*, p=desired phosphate increase and m=volume of product to use in mL. For example to raise 20 gallons* to 0.1 mg/L phosphate you would use: 0.8*20*0.1=1.6 mL."

If you compare this with fertfriend your calculations should match up. I remember doing this a while back and the ppms matched up.

Cheers

 

[torque6]

hi orion thanks for heads up. I didnt look up the main website, just the label on the back of the bottle. Seems if i were only give the total ppm of the bottle, i need to apply the similar formulae as in the case of sechem nitrogen for the phosperous as well.

Thanks again for your help. Much appreciated.