TDS readings and organics

[Chiefsmokingbud]

OK, ive always been under the impression that you canot measure organics with a tds meter accuratly because organics don't contain the salts synthetic ferts do. I mixed up a batch of tea last night consisting of:

5tbs peruvian bat guano
3 tbs maxicrop seaweed extract
3 tbs humic scid
5 tbs molassis

to 5 gal of RO water 30 ppm

After first mix i checked the meter and i had 650 ppm. I inserted my airstone and bubbled it for 24 hours. This morning i woke up and there was a nice foam on top. Check the meter this morning and it was now at 850 ppm????????????

So obviously the beneficial bacteria have broken down and turned something into somthing my meter can read......can't be salts so how am i getting a measurement?

 

[Guest]

I've wondered the same thing chief.. it is unfortunate that so many people are willing to assert that organics dont register on a ppm meter, yet you're post goes unanswered for weeks

 

[Suby]

Hey Chief,

I'm going to make a huge leaping assumption and guess that if you tea was successfully colonized (foamy) and that the microherd is making organic nutrients readily available to the plants in ionic form then it's likely ECF will rise over time, EC being a measure of electrical conductivity due to ions in suspension in water.

I'll be trying that, I'm just surprised the tea colonized as you did not use a source of bacteria like compost or worm castings.

Peace

Suby

 

[Suby]

From a website for Metanurals, it doesn't directly apply to your situation but it does reinforce the idea that EC readings are a little subject inaccuracy with organics.

Conductivity
MetaNaturals organic nutrient formulas mask TDS readings significantly. Many organically derived elements conduct electricity less effectively than do non-organic elements, leading to a very low EC/TDS reading. Set aside the EC recommendations for non-organic nutrients. Keep a careful record of daily EC/TDS readings and plant performance as soon as you begin using organics. EC readings in organic formulas will not be consistent with readings in non- organic formulas, but they will be consistent on a day to day basis. Develop new EC expectations based on daily readings and observations of plant growth and health. Note that your daily EC readings may increase as the microbial populations converts more of the nutrients into a form that the meter can read. This does not mean your nutrient is getting stronger.

 

[Chiefsmokingbud]

Sub i appreciate the knowlege you've added to this forum but im surprised that your surprised that there were enough beneficials. Guano is actually loaded with beneficials and very similiar to castings, just stronger. This year i'm doing a "legal" hydro garden outdoors using aero tubes (converted to drip/nft) and water farms. I'm going to be using PBP on some and straight guano tea on others. I hope to develop some kind of comparision base line for tds readings when all is said and done. Maybe shed some light on this mystery. I've got Peru seabird, Jamacian bat, Indo bat, and Mexican bat guanos, Plus castings from my worm farm so it should be a blowout organic season.
Just started a batch of Jamican tea that started out at 200 ppm.....we'll see how much it rises.

 

[Suby]

Hey chief,

PBP kicks ass in NFT, I've never tried that but I had built the systems and I still have it.
I've read that NFT is great with organics and you've got me wanting to set it up this summer for veggies.
I'll have to test the EC of some of mine and see what it works out to, I wonder if different kinds of guano with different N or P ratois measure up EC wise.

Suby