Sediment myths, heatin cables and ADA PS facilitate O2 diffusion

Tom Barr

Staff member
Jan 23, 2005
I've heard this from various critics for a long time now.
I've also not heard or seen any support for their claims.

However, I'm not out tp prove or argue that they do either:D
I think otherwise based on my background, observations and test.

Sediments can go anaerobics, no doubt here, but this takes more and more organic matter to do this also, aquatic plants do poorly when the % OM reaches about 10% or more, Barko show this in the past fairly clearly.

So roots do have limits to the amounts of O2 they can pump into the sediment.
Ole has recently done some studies that lok at O2 movement within plants.

Wiley InterScience :: Session Cookies
The resulting oxygen deficiency is considered to be the major problem for submerged plants. Oxygen microelectrode studies have, however, shown that aquatic plants maintain relatively high internal oxygen pressures under water, and even may release oxygen via the roots into the sediment, also in dark. Based on these results, we challenge the dogma that oxygen pressures in submerged terrestrial plants immediately drop to levels at which aerobic respiration is impaired.

I've seen this in HC and the DSM many times, many critics suggested a terrible case of transition. I saw the opposite, likely due to more nutrients that where starting to get depleted over time from the seidment or higher rates of growth due to sediment and water column sources of nutrients(no transport needed).

But one thing that gets overlooked time and time again are the plants themselves.

They can transport a lot of O2 day and night into the sediments.
They have to!
Roots respire after all.
There's little to no O2 there, so they have to transport it, this is major difference between terrestrial plants and aquatic plant roots(some terrestrials have it as well, but all aquatics do).

Why is this omitted from ADA PS claims? Or heating claims?
Why is there no redox evidence or OM evidence fro root growth rates that suggest there is an advantage here?

I need something more,I need these biological issues addressed before I buy into any of this. Someone needs to present me with a convincing argument that can answer such questions.

Every critic avoid the questions and repeat what has been marketed. Nothing more. Is there more to it that their market parrot repetitions and faith?

First is was heater cables, now it's ADA PS.

What next?

Tom Barr