# Lucas Formula

Discussion in 'Advanced Growing Techniques' started by tinh2, Sep 24, 2009.

1. TDS @ 0.5 conversion:
0-4-8 = 473 ppm
0-5-10 = 592 ppm
0-8-16 = 947 ppm

TDS @ 0.7 conversion:
0-4-8 = 663 ppm
0-5-10 = 829 ppm
0-8-16 = 1326 ppm

I have a question about the "Conversion" in the lucas formula.. What exactly does this mean? I have searched again and again and I am still confused. I am using this TDS meter TDS-EZ Water Quality Tester - HM Digital. This is actually my first ever post. Help me out! Thanx!

2. He's referring to the conversion factor the the TDS pen used for converting PPM from EC. The pen test the water electrically ( EC = Electrical Conductivity) and then converts it to PPM ( PPM = Parts Per Million)

Here a good explanation.

3. Very good explanation sir!! +rep

Ther are different conversions for different origins and uses so knowing "your" meters conversion is important.

There are x500/x700 and x1000 pens out there(x1000 were made for fish tanks)There are conversions which are slightly higher of lower too for some reason but so slight it wont matter.

There are adjustable pens with adjustable conversions too.

Lucas uses x500 FYI.

• ### Find Us On

© Copyright 1999 - 2022 Grasscity.com is a part of High Tide Inc. Company | All rights reserved