ok here's a bacis/Physics/'aqua-study' question.
Does any one know how deep a venturi will work to produce bubbles?
If the bubbles have to travel down a pipe then back up again(see diagram) where would the best place to put the venturi be? at the filter or nearer the heater chamber?

matt

The flow of water from the pump / filter, the diameter of the waterpipe and the air inlet pipe will determine the amount of air drawn in which will reduce considerably as you lower the venturi outlet. I have venturi on some baby filters that will only fnction about half an inch below the surface, but on a 4000 lph power head you get about 5" below the surface no problem. You will have to experiment.

The purpose of the venturi is to increase oxygen levels, mainly by greater surface movement of the water, so I am not sure why you would want to run it into the heater chanber at all, just water passing through there would be fine.

the filter/heater are built into a background ( the diagram is looking at the back of the background)and i didnt want to add an airpump even tho i have a spare one.
i half also used the venturi in fry tank but as a waterfall effect by reducing the flow thru the outlet.in another tank i couldnt get it to work at 3in depth.

thanks for the reply
matt

Matt

As I said earlier the purpose of the venturi (or an airpump) is to increase oxygen levels, mainly by greater surface movement of the water, so with that set up there would be no benefit, even if you managed to get the venturi to work down as far as the heater. Just run the filter return past the heater, forget about venturi and if you need additional circulation you can install an airstone (from your airpump) in the tank later.

OMG that means trying to drill a hole thru the background............ i think i might put one in now b4 its in place!!!!
thanks again .
matt