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Discussion Starter · #1 ·
I looked into this agian at the bequest of another.

- Earthworm castings are an odorless material used for years in the fortifying of terrestrial growing soils, providing an abundance of nitrogen, phosphorus, potassium, Fe, Ca, Mg and traces. Available nutrients are provided in forms readily used by plants.

If you boil it and dry it, you add O2, which will oxidize these elements, this is not the reduced forms, therefore these are not realistically "available" nutrients anymore than is rust.
Fe2+=> Fe3+, NH4=> NO3 etc.

- "Castings are a finely divided peat like material with excellent structure, porosity, aeration, drainage and enhanced microbial activity." [Dominguez, et. al., 1997]

The structure, peat like nature, porosity sizing, microbes are destroyed by the boiling process. You are rinsig out most of the good stuff here but getting rid of the Urea/NH4 which is good.

- "Earthworm excreta (castings) are an excellent soil-conditioning material with a 'natural time release' for releasing nitrogen into the soil." [Hams, et. al., 1990]

In terrestrial soils. Not wetland soils.

- "Scientific studies show that worm-worked composts have better texture and soil-enhancing properties; hold typically higher percentages of nitrogen, potassium, and phosphorous; and may offer plants disease-fighting properties." [Edwards, 1988]

Again, in terrestrial soils, you cannot compare wetland soils and terrestial soils, they are distinctly and dramaically different, ask any soil scientist.

- "An important feature is that during the processing of the wastes (manure) by earthworms, many of the nutrients they contain are changed to forms more readily taken up by plants, such as nitrate nitrogen, exchangeable phosphorus and soluble potassium, calcium, and magnesium. The most surprising result of our research was that even 5% of worm-worked mixtures had a significant effect on the growth of plants." [Edwards and Lofty, 1977]

As above.
If you want the most available forms of a macro nutrient like Nitrogen or K, add KNO3, KH2PO4 or NH4Cl etc.
The inorganic forms are the most available, most plants cannot use the organic forms, they must first be remineralized by bacteria.

It still gets down to the basic elements no matter how you skin this cat.
So adding KNO3/KH2PO4/traces/CaSO4 etc and peat etc will do the same thing. If these leech out, so will the EW casting's nutrients.

- "By shredding organic matter and contributing nitrogen, earthworms stimulate microbial decomposition. Soil microorganisms live in the worm's gut as well as the surrounding soil and so the microbial content of casts is usually more concentrated than in surrounding soil. Microbial activity in casts improves soil structure by encouraging aggregation of particles. [Edwards and Lofty, 1977]

If macro dosing in the substrate is so good, why does jobes have little effect? Wouldn't leechig out or converting the NH4/Urea in them do the same thing?

Many folks here have added jobes, one person added a fair amount and is doing a similar thing with his/her tank, McFinn.

He/she did not leech or boil out the NH4/Urea, but does daily water changes. But both that method and this one with worm casting can be done to high level if you so chose.

But there is no real mystery as to "why" it works and I still do not find any evidence that it helps reduce algae anymore than any other method.

I dose very liberally to the water column as I have in many tanks for a long time and at higher light than most folks and with no herbivores or fish in the tanks(no Organic components, NH4 etc). A crowd came in and bought most of the plants out of that 20 gal for the plant fest.
Other than plain aged flourite, I add nothing to the substrate. It was vacuumed and I only add OM, mulm to new tanks. So it was fairly clean/lean.

You still have to dose traces and adding some macros at the same time is not that hard if you do that already.
Fish loads also contribute macros namely Nitrogen.
Tap water?????? What is in their tap water?
That is something no one asked them or what test kit/method they used.

If all you have is some products at a LFS that are not macros, adding this will greatly enhance your tank, adding any macros will:)

I suspect they might have some macro's in their tap, but certainly not enough.

Adding the tap water, the EWC, and the fish load seem to staify the plant's needs.

Doesn't matter where you add the macros, as long as you do add some.

"Old dirty sand" was used by the Dutch for years, you can save mulm and dry it out, something I suggested a few years back and add that also.
they also have high PO4/NO3 in the tap water, lower light etc.

I think what is new today is higher CO2 levels and higher light, removal of the NH4 from faster growing more frequently pruned substrates.

These are key elements that many of these planted CO2 enriched tanks share.

Tom Barr

852 Posts

Would you recommend a substrate of earthworm castings for, say, a non-CO2 tank?

Would similarly rich substrates pose a problem?

2,072 Posts
Discussion Starter · #3 ·
Non CO2? Sure, why not.
Dried mulm works also.
Boiled soil.
Any organic manure.

You can add a bit more OM rich substrates since the light is lower, the CO2 is limiting/growth is slower and most do not add anything other than fish food to the water column, so no dosing to the water column. You have to have some source of nutrients for the plants somewhere.

So you will get much more out a rich substrate with: less light and less CO2. This slows down the rate of growth and allows the substrate to last longer and prevents uprooting and pruning as frequently.

Tom Barr

2,072 Posts
Discussion Starter · #5 ·
That's the point, none of these nutrients are "avaiable" or somehow organic since you just sterilized it and boiled the ****ens out of it.

Wetland soil is radically different than terrestrial soil also. There's no gas exchange.

Tom Barr

2,072 Posts
Discussion Starter · #7 ·
For starters we do not know what the tap water has in it.
Second: test kits
Third: fish loads and feeding

I had great growth and everyone else wondered why till we tested the water and also asked the local water dept about the PO4. Many Dutch tanks in the 1970's had high NO3 and PO4 and added traces with K+ and suggested large water changes(why was that?).

So if there's both NO3 and PO4, and a fish load and some in the substrate, then we can figure out where the nutrients come from.

I'll tell everyone this: NPK does not magically appear and plants do not grow without a source nutrient. In order for any 2 box model to work, there is an export and an import of nutrients.

You cannot keep removing gobs of plants without also adding nutrients from some source. The substrate will last only so long, even rich substrates used for raising ornamental plants are repotted every 3-6 months. If you want to replant/repot your substrate every year or so, feel free, I have no problem adding KNO3 from above.

Think about how much pure KNO3 you might add for a tank, say a 20 gal, over the course of a year and add that up and see if the amount of EWC's are more or less.

3 per week X 1.67 grams X 52 weeks = close to 260 grams, about 1/2 pound of pure KNO3 or about 1/2 a bottle of stump remover on the bottom of a 20 gal tank.

Why would that not be any better than EWC? Because you cannot get KNO3 there in many countries.........Got to make do with what you got.

You could use soil with the same results I'd argue or any manure.
There's nothing special about EWC really.

The organic consitutents are going to be remineralized to NO3, PO4, K+ anyway before the plants will use them and having it in the substrate is not going to prevent algae.

Slower release of these means it will be tougher to measure at low levels when you have hungry plants, so the test kits are especially suspect when measuring such a low level nutrient, as you also need a standard to compare the test method against.

Not doing so means you are introducing assumptions and cannot say definitely much of anything really.

I do not subscribe to "magic water, miracle cures, snake oils or maybe there's more than I know going on".

I'll look at it critically and try to figure out why something works.
Some fools think I have some "agenda" but I'm just curious about why things work the way they do and set out to find out why rather than spreading myths.

Somehow if they cannot get KNO3 or do not want to pay the 60$ for a kit etc, then getting a Lamott kit is also unlikely which is one of the very few kits I have much confidence in.

Maybe they do have Lamott kits and have done through testing, no one here did till some folks here in SF looked into it about 8 years ago. So it seems unlikely they did also.

Low tech approaches seldom have high tech testing.
This seems to be just that, will it help your tank?

I suppose if you believe that a lean water column provides better growth which is not supported in the literature in controlled studies nor in my own tanks, or if you believe lower water column NPK helps prevent algae, again something that is not supported and is shown to be false.

I think the main thing is that KNO3/KH2PO4 etc are not available there.

Adding stuff to the substrate has always been popular from the beginning of planted tanks long before CO2 and high lights came along

Adding the NPK to the substrate and getting some from the water column/fish loads also adds just enough for their level of lighting.

Boiling the EWC removes the algae causing componet, NH4/urea.

How much N and P come from the EWC? That is tough question without enriching it with 15N and labeled PO4. But you can get a close idea based off water column dosing and working backwards to find out how much is just enough NO3/PO4 etc to support a planted tank at a given light/CO2 routine.

You cannot test the substrate with any test method that the hobbyist has.

Tom Barr
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