Soil substrate pond

[MitchM]

A suitable level of diversity is not realistic in a small system. This is why small ponds have more frequent problems and require more maintenance than larger ones.

Next, how to determine what is an appropriate size for a truly self sufficient system.

 

[MitchM]

I got 2 bags of this: Eco-Complete planted aquarium substrate http://www.amazon.com/CaribSea-Eco-...1443200811&sr=8-1&keywords=aquarium+substrate

I think I wont have to get anything else. I read the comment and it seems the be good stuff.
My husband got me a high tech CO2 set up for Christmas last year and I've been using it but didnt see any different for my plants.. I even got a new light fixture (2 56 watt). So hoping the problem was that I didnt have the substrate and that this would help my plants.

Nepen, I don't know if you are interested, but this is a beautiful plant that has large lace like leaves that also have allelopathic characteristics ( algae doesn't grow on the leaves).

SPATTERDOCK Nuphar Japonica

 

[Meyer Jordan]

Next, how to determine what is an appropriate size for a truly self sufficient system.

No scientific data to prove it, but in my experience somewhere in a pond capacity range of 1200-1500 gallons a line is crossed where self-sustaining stability begins to occur.

 

[MitchM]

Would that be with or without a healthy substrate?

 

[Meyer Jordan]

Would that be with or without a healthy substrate?

Sorry, I should have included the fact that all of these ponds were rock and gravel. Yes, with a bottom sub-strate.

 

[MitchM]

For the record, I don't consider gravel and rock to be a healthy substrate.

 

[Meyer Jordan]

For the record, I don't consider gravel and rock to be a healthy substrate.

Please explain.

 

[MitchM]

I consider gravel and rock to be areas where detritus initially accumulates.
Detritus is fish mucous, feces, dead algae and bacteria, bacterial floc and dead plant matter that falls to the bottom of a pond. Until a substantial amount of detritus builds up, the bacterial population and diversity does not exist that can completely process the organic matter.
I consider what is there to be a "young" substrate, one that lacks the the diversity to completely process the organic material into nitrogen and CO2. Because it lacks the diversity, excess nitrates are released into the water column, contributing to excess algae growth.

 

[Meyer Jordan]

I consider gravel and rock to be areas where detritus initially accumulates.
Detritus is fish mucous, feces, dead algae and bacteria, bacterial floc and dead plant matter that falls to the bottom of a pond. Until a substantial amount of detritus builds up, the bacterial population and diversity does not exist that can completely process the organic matter.
I consider what is there to be a "young" substrate, one that lacks the the diversity to completely process the organic material into nitrogen and CO2. Because it lacks the diversity, excess nitrates are released into the water column, contributing to excess algae growth.

I am assuming that you are speaking of a new pond.
First lets clarify what is being discussed. Apparently what is being discussed here is the formation and maturing of the Benthic layer. A sub-strate is a too general term that can be applied to many submerged surfaces.
Within a few hours, the initial Benthic bacterial biofilm has formed and algae has started to grow, both sessile and planktonic. A mature biofilm will have developed within a few days to several weeks depending where the body of water is classified in the Saprobian System. All water contains some level of Nitrate and Carbon, both organic and inorganic, so initial biofilm formation and colonization is not usually inhibited. A new body of water (pond) will also immediately begin accumulating organic matter...plant litter, insect and animal feces, etc. which ensures a steady stream of nutrients to the developing periphyton whose growth rate is in direct proportion to these available nutrients. This is assuming that other factors such as DO, temperature and available light are at levels conducive for growth. In ideal circumstances, the dynamics of the Benthic layer and accompanying Benthos are sufficient in converting the detritus before it has a chance to accumulate to any great extent, but, over time, as the body of water becomes more Eutrophic the bacteria cannot, because of the limited amount of SSA, keep up, so to speak, with the amount of detritus that is collecting. This is the beginnings of 'muck' accumulation.
Excess Nitrate is usually extant because of the lack of live plant material (Macrophytes) at a level proportionate to the organic matter being added to the body of water, the result....algae blooms.
The composition of the Benthic sub-strate does play a major role with silt being the least desirable and wood being the most. Interestingly, in lab experiments, plastic proved to be a good sub-strate. One of the main controlling factors in sub-strate suitability is the size of void space within the substrate. Silt and Clay, though high in nutrients, possess the least void space restricting the passage of DOM (Dissolved Organic Matter). Gravel, on the other hand, has a large amount of void space which allows for fairly unfettered flow of nutrients. Wood, because it is totally organic and porous, blends the best of both. No naturally occurring benthic sub-strate is ever exclusively comprised of only one material. It is usually a blend of sand, gravel, clay, and rock dust and, over time, silt. This is basically the benthic sub-strate in my pond and what I have used in several client ponds.

 

[MitchM]

I am speaking about both new and old ponds with only gravel and rock on the pond floor.
Gravel and rock will have organic matter accumulate in it's large crevices, but that organic matter alone does not contain any mineral composition (clay) that adsorbs heavy metals and phosphorus. Periphyton must be exposed to the water column, otherwise once it is buried by detritus accumulation, it only becomes more decaying organic matter.
When I refer to substrate, I'm including both the organic and mineral components of the sediment layer on the bottom of the pond.

If you consider the three tanks that I have running:

Test tank has significant string algae and cold water, no plant filter
320 gallon tank has no string algae and cold water, with a plant filter
600g tank has no string algae and warm water, no plant filter

All 3 tanks have identical garden soil substrate and little to no water circulation. The 2 cold water tanks receive identical feedings of identical food. 600g tank receives heavy feedings daily. No tanks have a mechanical filtration device. The plant filter on 320g tank has a substantial clay component to it's media.

Because test tank and 320g tank are the most similar and both having slow to moderate plant growth, my observation is that the presence of clay in the 320g tank is preventing phosphorus from being available for string algae.
My explanation for no string algae growth in the 600g tank is that the warmer water is allowing for more vigorous plant growth, including some plants that are blooming, therfore incorporating excess phosphorus into the plant tissues. Frequent prunings have been required, so at that point phosphorus is exported from the system.

So - warm water may allow for more vigorous plant growth, preventing the growth of nuisance algae, but when there is cold water and low plant growth, the presence of clay is an important component for keeping a pond clear of string algae.
Because clay is a composition of minerals, it does not float, so it becomes a part of the substrate.

 

[Lisak1]

Just kidding... Kind of! I'm enjoying this conversation and @MitchM 's experiments. And definitely looking lots of things up!

 

[MitchM]

Lisak, I'm more familiar with salt water deep sand beds that have no plants.
This freshwater environment with plants that can be both submerged and emergent is new to me for the most part.
If I can explain things better, please ask.

 

[MitchM]

No they did not do well at first. When I first started adding plants they just died in the beginning. And I would throw them out. BUT when I added the plant on the right of the second picture (long green leaves) it appeared to have died but I didn't take the roots out, I forgot. After a few weeks I noticed a few leaves coming up and it came back in full force. It grows so well. It multiples by putting off little plants at the tips of the leaves.

The plant on the left of the second picture with the redish leaves seems to put out new plants from its roots. I have been able to divide some of these too. It doesn't grow as fast as some of the others.

The plant in the middle of the first picture with the wider leaves stayed as I bought it for a while and did some algae on it and I thought it would rot, but after a few months it took off. I trim it back and give it away.

I should have gotten better pictures but it was late and the kids were sleeping so I didn't want to disturb them, I realize you can't see the full tanks. But its the same four or five plants in them.

I guess maybe they go through an adjustment stage when they change tank/water but once the adjust they seem happy.

I think what is happening is that in the beginning there was not sufficient nutrients available, so plants did not do well.
After a period of time, sufficient nutrients built up from detritus accumulation so that the plants you now have are able to survive and grow.

 

[MitchM]

One thing that I'm not able to account for is allelopathy (chemical warfare) between the plants.
When I purchased the spatterdock nuphar japonica I was told that algae will not grow on it's leaves because it's leaves contain a chemical that prevents algae growth. I don't know if that chemical is being released into the water column of the 600g and preventing algae growth.
Willows also contain an algecide chemical, salicylate, which is included in some anti algae freshwater aquarium products.
I was able to sucessfully grow some willow branches by take some root cuttings and suspending them in the 600g tank.

All I could really do in this regard is circulate some tank water through activated carbon and remove chemicals through adsorbtion.

 

[Nepen]

What do you mean by "hi tech CO2"?
I had an aquarium way back when that I piped the CO2 to my aquarium from some wine that I was fermenting. It worked well, except my apartment smelled like a winery.

I meant the CO2 system that's not DIY lol