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Discussion Starter · #1 ·
The substrate that we have in our aquariums, be it the best aquarium ready substrate, kitty litter, potted soil, or your special, will have a limited life in our planted aquarium condition. It is sure to go stale in near future or a little further if you are low-tech. Then you will have to redo your aquarium again. I do enjoy doing up an aquarium but then I hate to disturb the plants and the fishes I got to get into their prime.

Next time I am doing up a aquarium, I intend to put a coil of perforated 6mm PVC tube on the aquarium floor before covering with my own special substrate.

In natural water-bodies nature has eternal substrates which do not go stale with time. It is not the removal of debris in aquariums alone that makes our substrate go stale. Our aquariums have population density of fishes far greater than in nature, removal of debris would not cause the substrate go stale there is enough debris left over after our removal to provide food for the soil and plants. It is the lack of penetration of this food into the soil which makes our substrates go stale. Hence the coil of perforated PVC tube on the floor.

I am going to connect the two ends of my coil of perforated tubing to the two sides of a T, and then connect a non-perforated 6mm PVC tube to the third side of the T and use it as a siphon.

In nature, water leaches into the soil, very slowly or the water-body would run dry. This carries some oxygen and nutrient for the micro-organisms in the soil. The fresh nutrients allow the micro-organisms to replenish and multiply. Healthy micro-organism condition and refresh the soil. In our aquarium this is prevented and so the soil goes stale. Hence the siphon connected to the coil.

I am going to connect drip irrigation nozzle/nozzles to the end of the siphon and end it in a sump under the aquarium.

I don’t like run-away leaks, and I would like the out-flow low enough not to draw water strongly enough to block the perforations. I think this way I will be able to create for myself an ETERNAL SUBSTRATE for my aquarium.
 

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Define stale.

Do you mean nutrients running low? That doesn't happen with something like Flourite. The minerals in Flourite will last pretty much forever. Any other nutrients are constantly renewed from fish poop and plant debris. The last two of course depend on the fact that most of us with planted aquariums don't do a lot of deep gravel cleaning.
 

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Well, things come in from the tap water and the fish food, or ferts.
Low tech tanks can run for 100 years using the same substrate, but you need to add something to the water column, most do they call it fish food.

Many folks have tanks that are 5-10 years old with the same old substrate.
If you are referring to the substrate running out of nutrients, that does not matter if the water column has some as well.

If you search on the APD and under CPVC, I made a reverse UG filter with a grid, perhaps similar to your notion about 15 years ago.

Comparisons to natural substrates are not really what you want for a standard, they are limiting growth in most cases. The organic matter is loaded and it reduces O2 levels way down, accretion rates are important.

Healthy micro-organism condition and refresh the soil.
Well, it'd be better to say they mineralize the soil from the organic forms into bioavaiable forms. The best way to do that, at least in terms of speed, it through aerobic methods.
This occurs normally in tanks.

If you take your notion to the logical conclusion, a UG filter should do the same thing as you desire, just slow it down.

But clearly we see better growth without them, but those tend to be faster rates, heating cables also made similar claims.

I suggest you look at some growth rates of various sediments and you can see how well the grow vs others.

If you slow things down a lot in term of low tech non CO2 slow growth tank, then the age of the substrate becomes portortionally less important as well.
Much more contribution comes from the water column in terms of fish waste which plants will take up just fine via the leaves, never needing to use their roots except for some trace metals perhaps which can also be added to the water column easily.


Regards,
Tom Barr
 

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Discussion Starter · #4 ·
I don’t mean lack of nutrients and I don’t profess to know what goes on inside the substrate, it is an acknowledged fact that we do not know 90% of the organisms that live in the substrate on land or water, far less their interactions.

What I do Know is:- Plant roots create an aerobic area pumping oxygen into the soil to make the soil habitable to its roots. They also exude many chemicals into the soil for helping them to absorb nutrients. Plants exude some chemicals for excluding competition, some of them very phytotoxic. They also may be exuding other chemicals too. The substrate also contains hundreds of other organisms, both macro and micro, and all of them together create the substrate ecology. After the initial growth of the plants their requirement of minerals reduces as most of the minerals in the discarded parts of the plant are reused.

Observing the plants in aquarium, especially when they are being foliar fed, will not disclose the health of the substrate, except perhaps new plants are harder to establish. Even then the activity of creating a fresh space for them might help reconditioning the substrate.

The staleness I speak of is the condition of accumulation of chemicals due to stagnation. In nature the leaching of water would help reducing the accumulation, and also bring into the substrate fresh useable nutrients.
 

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Discussion Starter · #6 ·
Thanks aelysa. Looking for something like that hose for my climbing rain forrest plants.
 

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What I do Know is:- Plant roots create an aerobic area pumping oxygen into the soil to make the soil habitable to its roots. They also exude many chemicals into the soil for helping them to absorb nutrients. Plants exude some chemicals for excluding competition, some of them very phytotoxic.
Such as?
You said you know of some, please elaborate:thumbsup:
Show me one that's been shown in the environment.
Just one case, one study that shows that it occurs in a lake somewhere, anywhere.
Quantify the toxicity. Are they toxic to other plants also?
How about fish?

There are several primary peer reviews on the topic out there.
I suggest you read their conclusions.

Gopal, B. and Goel, U. (1993): Competition and allelopathy in aquatic plant communities. The Botanical Review, 59:155-210.

At the hobby level:

www.bio-web.dk/op/pdf/TAG_2002_15_7.pdf

Search the APD and me and activated carbon test.

Re: Alage, bacteria, nutrients, allelopathy

[APD] RE: allelopathy

That combined with Ole's support really put the nail in the coffin on this topic.

They also may be exuding other chemicals too. The substrate also contains hundreds of other organisms, both macro and micro, and all of them together create the substrate ecology. After the initial growth of the plants their requirement of minerals reduces as most of the minerals in the discarded parts of the plant are reused.
Is it required to know what the organism are or merely how they impact plant growth? Since that is the basis and much simpler method to resolve the question at hand rather than trying to learn every possible critter?

We'd never get anywhere assuming that we must know everything first........
Focus and rule other things out.

Observing the plants in aquarium, especially when they are being foliar fed, will not disclose the health of the substrate, except perhaps new plants are harder to establish. Even then the activity of creating a fresh space for them might help reconditioning the substrate.
Actually it will, it gives a good comparison for a baseline to show differences between substrates, non limiting water column is ideal, as any growth differences are solely due to the substrate affects at that point.

If you have limiting water column differences/issues, then it is obviously MUCH harder to distingush various types of substrates for our plants.

Limiting the water column basically makes your analysis much more complicated.

The staleness I speak of is the condition of accumulation of chemicals due to stagnation. In nature the leaching of water would help reducing the accumulation, and also bring into the substrate fresh useable nutrients.
But you also state that the roots import O2 ansd aid in bacterial respiration, so which is it? :icon_ques

Are you suggesting that both stale and non stale places exist in the same substrate?

Why might "staleness/stagnation", or more precisely, lack of diffusion, be bad?
I mean how could the chemicals that are detrimental get there and stay if they cannot leave also? Stagnation is not the issue. What is the issue is the loading rate of organic carbon into an aquatic sediment.

Now that organic reduced carbon has to get down to the bottom of the sediment in the first place. That's not going to happen if there's no diffusion from above down there.

I suggest folks periodically refresh and fluff up the substrate, vacuum it deeply once a year etc. This removes the excess mulm, organic matter, and exports it and allows for good circulation.

Pipes, heating cables etc only speed the clogging up, it makes it act like a gaint sand filter, or a UG filter.

This is why no flow at all produces the best growth rates in aquatics plants. I've seen this, Tropica has, but maybe we are wrong? Perhaps we have assumed something wrong?

I've done a lot of background research, familiar with each process in the biogeochemical cycling in aquatic hydric soils, and have done a lot of more test on substrates and flow rates of diffusion. I have no issues with debating the topic.

But you need to read up so you better understand the issues and learn, then you can debate and not buy into the baloney and speculation.

See what others have done in the past, that way you do not waste your time on things that folks have already done.

Most of the allelopathy studies that support these folk's contentions tend to be highly cocnetrated extracts from a few species, and added to small test wells.

There has never been any study to date that shows allelopathy exist in an aquarium with plants or a lake etc.

If you think about it, wouldn't plant-plant allelopathy be a more significant pressure evolutionarily? Should submersed plants try and kill of the floating weeds that block light? We do not see that either.
How does the plant know how big the tank, lake etc is? Flowing water? These are massive issues with how well such chemicals might work or not.

You can do a simple test, add activated carbon to an otherwise stable tank, if you accept the allelopathic hypothesis as a mechanism for algae control in planted systems, you should get algae with this treatment. AC removes all allelopathic chemicals and is a standard control for these studies in terrestrial systems. I did it, it made the water clearer and cleaner was all.

Regards,
Tom Barr
 

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Please note, I am not trying to discourage you in any way, quite the opposite, give you some insight and things to think about before doing this work, be careful with your readings, assumptions and ask basic questions about what you see.

That is why I post more than most.

Regards,
Tom Barr
 

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Quite frankly, and no offense to any other member, when Tom speaks, everyone should listen.

I was always under the impression that in a healthy substrate, both aerobic and anaerobic bacteria existed in union to break down organic matter into useable nutrients for the plants and so I've never deep vacuumed my tanks.

Guess I'll have to rethink that strategy somewhat now.
 

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I got a friend with almost "eternal substrate". He really mimics nature at work, in fact his setup is indeed a part of nature.

When he taps a fresh water supply 24-7 from a natural spring that runs at his land and connect his gigantic tank into a private several thousand gallon worth of pond it cannot be wrong. No CO2, no fert, no manual WC... really envy how his system work.
The guy became quite a prominent plant supplier around here.

Mimic it from my house? now way. No way I can follow him with nature at his side :)
 

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Quite frankly, and no offense to any other member, when Tom speaks, everyone should listen.

I was always under the impression that in a healthy substrate, both aerobic and anaerobic bacteria existed in union to break down organic matter into useable nutrients for the plants and so I've never deep vacuumed my tanks.

Guess I'll have to rethink that strategy somewhat now.
Well, once a year with say a flourite substrate, it's a good idea, we have been using it for many years in the Bay area, and after 1-3 years, often things get a lull, it's not due to the lack of water changes/exchnage etc.

I think the ADA AS applies here as well, they tend to redo them 1-2 years anyways, a tank can and will keep growing, but you can a notable difference in the O2 levels and plant health after exporting the mulm.

They sell organic digesters, bacteria, enzymes, H2O2, Permangnate etc to decompose this sludge. But simply vacuuming once here and there is not a bad idea and removes the organic matter which is now too much and draining the O2 levels from the roots, and from the water column.

Some organic matter is good(Add mulm to a new tank!!).
Low OM sediments are also poor for plant growth.
Too much is bad and causes the substrate to go sour, (A rotten aponogeton bulb etc).

There's plenty of research out there showing that too much OM is deterimental to plant growth(See Barko and Smart et al), just because it's "nature" does not in anyway suggest it's balanced at that point in time and healthly for plants/fish etc nor optimal for horticulture.
That's an assumption that's been made and it's a bad one as it can mislead and cause folks to ingore obvious things.

I suggest folks deep vacuum their substrate in 1/4 to 1/3 units weekly till the entire substrate is fairly well deep vacuumed at about once a year.

You should do large water changes the day you do this as lifting up all that OM will decrease the O2 levels significantly and place fish under stress.

Afterwards, you see a sharp increase in clarity, pearling, vigor and better use of nutrients.

What this does is improve the inorganic fraction of nutrients and removes the lesser available organically bound forms. It improves O2 levels a great deal, allows the bacteria in the sediment to process the waste and plant leaves etc faster as they have more access to O2.

Now if you go too far with aerobic substrates, as is the case with RFUGF's, UGF's and cables, then you get lesser plant growth and other issues.

So a middle ground, mainly moderate to low OM loaded at a slow rate and mitigated but light vacuuming weekly/monthly of the surface of a planted tanks, fluffing etc when you do a water change etc.

We also export waste via filters, plant uptake/acquistion etc.
It's not a static system as some like to suggest.

Regards,
Tom Barr
 

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Discussion Starter · #12 ·
Some organic matter is good(Add mulm to a new tank!!).
Low OM sediments are also poor for plant growth.
Too much is bad and causes the substrate to go sour, (A rotten aponogeton bulb etc).

There's plenty of research out there showing that too much OM is deterimental to plant growth(See Barko and Smart et al), just because it's "nature" does not in anyway suggest it's balanced at that point in time and healthly for plants/fish etc nor optimal for horticulture.
That's an assumption that's been made and it's a bad one as it can mislead and cause folks to ingore obvious things.

I suggest folks deep vacuum their substrate in 1/4 to 1/3 units weekly till the entire substrate is fairly well deep vacuumed at about once a year.


Regards,
Tom Barr
Thank you for pointing me in the right direction for understanding substrate ecology. Actually my thread was started because of my observation of the benefit my plants had when I managed to deep vacuum a dense part of the planted area.
 

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Well, I think some like to spend 1000 hours of fiddling and work to save themselves 30 minutes iof work:proud:

I prefer to brush my teeth 2x a day vs getting a cavity filled every 3-6 months. Same deal here.
Some folks are different.

Overall, the flourite, EC, sand, ADA substrates should only need this once a year at most, does not really take that much time to do the work and water change etc, not a bad idea to re slpoe the sand and clean stuff good.

A clean tank always looks better than a dirty one.


Regards,
Tom Barr
 
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