Measure absorption rate of a fertilizer

wilamzq

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Joined
7 Mar 2019
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17
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Sweden
Hi guys,

I might making a stupid question here but THEORITICALLY, Can I measure the absorption rate of fertilizers in the water column using a TDS Meter? i.e monitoring 24/7 the EC for a period of time and after adding (for example 10 ppm NO3) which will increase instantly the TDS and then get the drop of the TDS over the next days..Maybe validate it with NO3 test before and after the addition?

Is there a similar technique to do that?

Thank you and excuse me for my ignorance!

Cheers
 

zozo

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16 Apr 2015
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Netherlands
The issue is it measures Total Dissolved Solids, the meter doesn't discriminate it measures them all and it doesn't tell you what. Among other things, when water evaporates it leaves the tank as Demineralized water and leaves all the solids in the tank. Then you top that off again adding extra solids on top from the tap also raising the TDS.

It's a conductivity meter that gives a number on how conductive the water is, the amounts of salts in it changes the conductivity. More salts gives higher conductivity. Usually expressed as Micro Siemens and this is converted back to TDS, EC or PPM.

In the end, you can't exactly know what the number indicates in relation to fertilizers. It could tell you the TDS is to high it's time for a water change that's about it.

https://www.ukaps.org/forum/threads/tds-meter-readings.59507/
 
Last edited:

Iain Sutherland

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7 Jul 2011
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Cambridge
It can give you a pretty good idea. I check this way with my shrimp tank to ensure tds doesnt climb, checking this every couple of weeks ensures ferts increase or decrease with plant mass...
Tds 180
Add ferts TDS 190
Next day TDS should be back to 180. If it isn't I reduce dosing.

As above, it isn't an exact science but as long as you top up your tank daily with RO it will a pretty good estimate.

Sent from my SM-G950F using Tapatalk
 
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