Fertilizer Testing Questions

[over_stocked]

Some of you may have seen my discussion of fertilizer testing on TPT. I am currently attempting to develop a substrate fertilizer. Primarily I am working on a delivery that seems to be similar to the FERKA capsules. I am not sure if anyone has experience with them here.

I have tried, and adjusted them 7 times now, and am ready to start with some more significant quantitative testing. This is why I have come to you fine folks.


I want to use plant tissue testing and biomass weighing to test this, as Tom has suggested. I will quote him for good measure:

You may "think" all day long and all you want, however, that is not going to answer anything. To do the test you suggest, you need to have the RO like water in the water column.

Otherwise, the nutrients entering the leaves will skew the test.

The best way to evaluate sediment and it's effect on plant growth is two/three part:

1. Dry weight biomass totals without interference from water column(eg, it must be independent) between the treatments.

2. Specific N and P content(or whatever nutrient of interest, Fe, Mn etc) in the dry weight biomass samples of the plant leaves and roots.

3. Measure the content of the product over time and at the initial stage

These can confirm the questions you want to know.
Otherwise, you are no better off than guessing.

I'm "happy with the results" of my exclusive arm pit hair dosing as well, but it provides little comparative analysis from other folk's arm pit hair dosing methods. hehe

You may have been under dosing the water column, well, then ....of course adding more sediment ferts will help, whereas when you have non limiting water column ranges, you no longer see much effect.
ADA plays this silly baloney game in their "supposed test" of their sediment test between plain sand and ADA AS. One sediment has nutrients, the other has nothing, there's no nutrients in the water column.
Of course even a brain dead person would predict more growth because one treatment has more nutrients and the other has none.
That's the only test they offered and it answers what anyone would already know.

What is needed is a comparative test that would show it works better than say MTS, delta soil, Osmocoat pellets, Jobes sticks etc.
Same for your product.

Also, is it a function of the user's errant water column dosing? Or is the sediment really the effect?

I totally agree with using sediment fertilizer.
But as synergistic part of total fertilization that includes water column dosing.
It makes management far easier for most hobbyist.

Folks forget to dose the water column etc, adding NH4 can help for long term supply in sediments, but not in the water column(fish work there pretty good), water column is easy to add etc and meter.

Few do either or, so testing it that way and the results will often be very skewed. So it will be difficult to rely much on aquarist observations independent of many other factors.

Why are you not doing these test yourself?
Your product, your $, your time. It is your test after all. You can pay labs to measure the parameters above for somewhat reasonable amounts.

You can just do without such test, but you really cannot say much, most root tab marketing stuff/claims copies eachother with their little sale's pitches. None I know of have done the above test. I think I'm one of the few who have in this hobby.

There's many other factors not accounted for and it might and might not offer much help to an aquarist, depends on many things(their habits, water column, CO2, light, type of plant etc etc).

Root tabs are easy to make, I can go out in the rice patties here and dig some clay wetland soil, mash them into balls, they are very similar to ADA AS.
I do not need to do the other test since they already have the data for the soils for rice, but I do not know what impact the soil will have on the 300-400 other aquatic plant species.

But since I know it's similar to ADA AS, I can predict somewhat well.
So you can go about it a few different ways to get around things.
Then be a bit better off in what you can/cannot say about the product.

Simpler test, think hydroponic like emergent aquatic plant shoots added to small flask and allowed to grow in various sediment/root tab combinations.
This rules out light/CO2/and water column dependencies between treatments.

It does not provide specific aquatic plant environment hobbyist keep, but it does answer the issue of the water column problems and CO2 etc, and makes the test much easier.
Try that yourself.


Regards,
Tom Barr

What i am interested in primarily is tissue analysis for P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B, Mo, Pb, Cd, Ni, and Cr and N. This test is economical enough for me to do on my scale. I will include biomass weight because it is simple enough.

My first questions:

What plants/cuttings should I use in my preliminary testing. What method of growing would you recommend? How many? I will use separate containers for each, have not decided on which yet.

Because I have little interest in making money off of this I will explain. The fertilizer is placed into the substrate using a gel capsule(I am testing vegetable caps right now too, for solubility, but they are more expensive) just like FERKA caps. I am trying to make this a comprehensive fert, but am open to suggestions for what to use.

I am open to any thoughts and suggestions. This is more an attempt to offer a really cheap, yet effective fertilizer that is superior to the common ones out there. I know there are many DIY options, but this is intended to be cheap enough for those who do not want to take the time( I know that is not most of the people here) to DIY a solution for themselves.


I intend to use a lab for some of the testing, but for a more economical testing could one of these tests work http://www.biconet.com/testing/pt.html or one of these http://www.google.com/products?rlz=...esult_group&ct=title&resnum=3&ved=0CBwQrQQwAg

Thoughts, concerns, criticisms, etc are appreciated.

 

[over_stocked]

I intend to purchase the micro and macro test kits, if someone thinks they are worth while.

 

[Tom Barr]

You might read the paper I did for a class search under "Phytometer", I think dry weight, leaf count, stem length etc, will be enough if you run say 5-10 common aquarium plants. The tissue analsysi is a bit much, but would be nice, that's additional confirmation.

If you cannot find the paper, let me via PM.

Regards,
Tom Barr

 

[yashaswibs]

Is this more of a hobbyist attempt at finding a good substrate fertilizer or are you attempting to write a proposal and grant followed by a paper?

If this former then is it any help to try to find individual analysis of different elements, especially if you are trying to just trying to grow plants?

If the bottom line is growth then dry weight comparison would be enough. Weeds of some sort would be a good start- some root feeders with rapid growth will allow you quick turn over of experiments.
Could you use three plants in each arm to provide some statistical significance?

Just a few thoughts from my angle.

 

[Tom Barr]

You can view the paper I did in the advanced fertilization section subforum.
I agree with you Yashaswibs, dry weights, stem elongation, leaf counts, root and shoot weight is more than enough for justifications, comparisons.
They could send out a few samples for say Fe, N, P to an ag service that test crops.
That would show a lot went in to the product and some baseline evidence to show it works.

Regards,
Tom Barr

 

[over_stocked]

So you wouldn't waste money on the plant tissue test kits? I get comprehensive sampling done for about 22 bucks a test, from other sources. If I did more than 5... that would pay for the NPK test. I'd have to have 10 tests done to pay for the micro test kit too.

Looking for a local testing option as well, since I live in the heartland!

I have always been interested in tissue testing, to see just how successful some of our dosing is, but am not really sure what I would have to use it as a benchmark. I think it would be handy to use in diagnosing a deficiency.

 

[Tom Barr]

So you wouldn't waste money on the plant tissue test kits? I get comprehensive sampling done for about 22 bucks a test, from other sources. If I did more than 5... that would pay for the NPK test. I'd have to have 10 tests done to pay for the micro test kit too.

Looking for a local testing option as well, since I live in the heartland!

I have always been interested in tissue testing, to see just how successful some of our dosing is, but am not really sure what I would have to use it as a benchmark. I think it would be handy to use in diagnosing a deficiency.

Well you could get them done, 22$ a smaple is not bad and it's an independent verified method outsourced.
I'd do N, P, Fe for 2 samples and then compoare them to sand and water only and maybe hoagland's modified.
That would give a lower and upper bound.

It should not take long, say 3-4 weeks of grow out. Chose a good plant.
Something like hoagland's you make etc, much like EI, but 5X more concentrated, then you delet what ever nutrient of interest and look at the differences.
That's how ag services do it and how Liebig, Hoagland etc did it for crops.

We can do this for nutrients, but not for CO2 using the flask, but you can do it ina sealed chamber and remove the CO2 to various levels to induce limitations.
Or try it in water.




Regards,
Tom Barr

 

[CL_]

This does sound interesting. I didn't know that you were doing this. I have used the ferka capsules for rosette plants, and they seem to work very well.

 

[over_stocked]

Sorry I missed replies. CL, if interested in trying this out, please shoot me an email at [email protected]

I am running some controlled tests now, but we are not even to the point of adding the fertilizer. Doing 2 weeks of no ferts to show comparison.