Trying to understand some of what I’m witnessing… the mechanical filtration of plants… a study of roots

[Magnum Man]

So, I have an over abundance of terrestrial plants growing out of my tanks… and a few floaters I’ve expiremented with… the aggressive growing larger floating plants seem to vacuum up and hold ( loosely ) a lot of solids… my experience there, is with water lettuce, and water hyacinths… the plants need to be removed and cleaned once a month, and yet I can have big root balls on my pothos, or Chinese Evergreen, and those roots remain white with no collection of solids these pothos roots have been in this tank over a year, with no maintenance needed…

 

[Magnum Man]

…. And yet these water hyacinths, have only been in this tank, similar filtration and stocking level, for about a month now

 

[Magnum Man]

The water Hyacinths collect more than they can hold, dropping solids below

 

[Magnum Man]

The pothos, don’t collect or drop any solids ( BTW, this is a 20 foot vine, so it’s likely drawing more water than the Hyacinths

 

[GaryE]

I always figured, with nothing to back it up, that floaters had evolved to trap debris and feed on it, while terrestrial plants roots in had no need to. They can thrive roots in, but it isn't their real habitat.

 

[Colin_T]

Floating plants have fine hairs on their roots, which trap gunk.

Terrestrial plants have a couple of different types of roots. They can have water roots and terrestrial roots. Not all land plants have water roots and many die if their roots are constantly wet. Some plants are fine with wet feet and these produce water roots. A small group of plants (Tillandsia sp) have air roots, which are slightly different to terrestrial roots. Basically terrestrial plants that have water roots don't normally have the fine hairs on the roots to trap gunk.