Strictly South American plants?

[dw1305]

Hi all,

Ammonia uptake by plants does not require oxygen and plants, if submerged, are net oxygen producers. Ammonia conversion to nitrate in the filter takes up oxygen by the nitrifying bacteria.

I agree about the plants and plant/microbe filtration, all my tanks are planted fairly heavily. I'm not suggesting that "just a filter" is an alternative to plants, quite the opposite I want every aquarium to benefit from plants.

There is a much more complete discussion of this in <"PlanetCatfish:using deep gravel...">, and linked threads.

What I don't know if the oxygen drain by the filter is a small fraction of the total oxygen cycle in tanks or a substantial fraction that, by switching to plants as filter, makes a real difference.

You don't have "only plants" as the filter, the point is that in a planted tank, it is still always plant/microbe filtration, you can't have "plant filtration" on its own. I don't think in our cases that the presence, or absence, of a filter makes any difference to the total amount of microbial filtration.

Plants can indeed uptake ammonium in darkness, but they can't produce oxygen in the dark. Without light or water movement, a solid mat of floating plants (leaves laying flat) isn't much different from a sheet of plastic layed across the water surface. Not much oxygen can diffuse in.

I agree with @gerald, it is pretty unequivocal that larger gas exchange surfaces produce higher levels of oxygenation at night.

cheers Darrel

 

[dw1305]

Hi all,

Is anybody using Eichhornia crassipes as a floater. ......I'm curious to see if fish will start spawning in the very dense root system that looks like the ultimate natural spawning mop. One of these in a 10-15 gallon tank may be all you need to absorb fish waste as they are one of the fastest absorbers of nutrients, at least in eutrophic waters. They won't block the surface as much as smaller floaters and won't stick to your arms.

It would be my floater of choice for larger tanks, for the reasons quoted, but I've never managed to get it through the winter. The only grow-lights I have of suitable intensity are in a glasshouse where it is only heated to "frost-free", and that isn't warm enough.

It is also now <"banned for sale in the EU"> (and several states of the USA), although it is never going to be invasive in Northern Europe.

cheers Darrel

 

[gerald]

I use Eichhornia crassipes in my outdoor tubs. Just before frost I bring about 10 small ones inside for the winter, put them on my sunniest windowsill, and watch them shrink down to nearly nothing over the winter months before I can put them back outside again in spring. Then it takes a month or two before they really start growing significantly. I'm not sure if it's light intensity, photoperiod, or an innate seasonal clock that shuts down growth from about Oct to Apr. They're too tall for my indoor tanks, which I keep covered. I'm sure they'd work great as a spawning medium in uncovered tanks, if you can give them the light they need.

 

[lexi]

I have thought about doing a more strict biotope style tank but havent done it yet. I think it would be a fun challenge. For now though, i have plants from multiple origins. My fish are mainly south american, with a few compatible exceptions.

 

[Mike Wise]

When it comes to apistos and natural biotopes - it's not a pretty site; thick layers of dead rotting leaves, sunken wood covered with algae and not many aquatic plants.