Howdy,
JardiniBoy said:
Anyway, harleyk/delgado ... what's the "other crap" that you mentioned. Is this something that you have read/studied or is it just a theory?
It's common sense. Try this

: Walk your dog and collect the poop. Put it in a blender with some water, then filtrate it thru a coffee filter (make sure you don't have a shake or coffee at home for at least a few months). Whatever runs thru the filter is dissolved organic matter, which stays in an aquarium with heavy bioload, few plants, and no water changes. The DOC (dissolved organic carbon) is actually monitored in waste water treatment plants. Besides that, ions are accumulated from food (mainly alkali metals, alkaline earth metals, halides and phosphate), dramatically rising to affect osmotic pressue, detectable by increasing conductivity.
Bottom line: try out the test above and see for yourself.
this isn't guaranteed to work but is absolutely worthwhile to look into, plants complete the cycle but the ever intelligent man has gotten around many obstacles and this may be another one that we can overcome (perhaps easily), the truth is this phenomenon has been observed much more than once, lets not be closed-minded and really look into this possibility
I am not being close-minded, I am being realistic. For some reason, the guy did not monitor or report the conductivity in his tank (FYI this is standard procedure in environmental limnology). Obviously, he was serious enough about it to sell his red & gold aros, but did not put much thought into his study design

Anyhow, if that data was available, this thread would have ended a long time ago ... with a few laughs...
You say it has been reported more than once ... maybe you can find data on conductivity changes over time. I am always willing to consider solid data in order to shape my opinion.
i say this because... look at the rivers and lakes.. they don't have water change every week. what they have is rain that adds up the water and plants that completes the cycle.
Lots of water changes in a river.

Consider it a humongous drip system.

And most lakes have either surface waters (creeks, streams,..) or sub-surface water flow (springs, groundwater,...). Put on a wetsuit and find out - you'll be surprised what you find under water.
The aspect with plants has been mentioned before, and it only works in a low-fish, high-plant tank...
Some of you guys almost sound like the inventors of Tetra EasyBalance ....
and remember: no coffee
HarleyK
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