Return line venturi... help needed.

[One_Cich_Dude]

After reading through 70+ pages of the overflow thread, I just had to join the site to get some advice.

I built an overflow similar to the ones being discussed here...

And I used a hybrid Stockman/Hofer standpipe to muffle the industrial toilet flushing sound.

I recalled someone mentioning using a venturi from a powerhead to prime the overflow in the event it loses siphon.

I don't want to buy a powerhead. I DO want to find a way to make a venturi in the return line that has enough power to prime the overflow.

A look at the wiki article on venturii shows that the concept is extremely simple. I just want to know if anyone has already made one from common hardware store materials so I don't go off trying to re-invent the wheel.

Thanks to the staff and membership here for a wealth of great technical information!

 

[One_Cich_Dude]

I tried 3 different powerheads today, and their venturi inlets did not have the strength to prime the overflow.

The overflow works fine for short power outage tests, the flow starts right back up again. But I am uneasy about it restarting if it remains idle for a long time. I'm going to have to let it sit for a few hours and see if it will restart.

 

[hybridtheoryd16]

The way you hook the line to the power head is a venturi. You can do the same thing on the out let of your pump. I would try it below the water surface of the tank. just drill a hole in the inlet piping going in the tank below the water line about the same diameter as the air line and push it in. Make sure it is in the pipe a 1/4'' or so maybe a 1/2''. And this will create a venturi using your return pump. But the question is, will it be enough and no one can answer that, you just have to try.

 

[Dr Joe]

Did you use the check valve with the spring in it (the other ones have a tendency to leak air backwards, which is normal since it was made to stop water (more viscus)).

There should also have been mention about a Aqua Lifter http://www.aquarium-supply.biz/Tom_Aquarium_Products_Aqua_Lifter_Water_Air_Pump_p/rcpr01137.htm pump too.

Dr Joe

.

 

[One_Cich_Dude]

Did you use the check valve with the spring in it (the other ones have a tendency to leak air backwards, which is normal since it was made to stop water (more viscus)).

There should also have been mention about a Aqua Lifter http://www.aquarium-supply.biz/Tom_Aquarium_Products_Aqua_Lifter_Water_Air_Pump_p/rcpr01137.htm pump too.

Dr Joe

.

I have seen the aqualifters mentioned in one of the overflow threads. I'm curious, are they designed for 100% duty cycle? If not, what's the best way to have them power up when the overflow loses it's siphon?

I have tried 3 different powerhead venturii of various make and power levels, and none was capable of priming the overflow.

I've almost resigned myself to becoming one of the defeated many who after spending hours and hundreds of dollars finally buys a commercial cannister filter.

 

[wow_it_esploded]

Are you trying to prime it the first time or take out excess bubbles?

*whispers* This is your self conscious... get an Eheim 2262 *finishes whispering*

 

[Ali1]

question never got answered. So How do i go about connecting the aqualifter to the overflow system?

do i replace the check valve with an airline into the same hole and the other end of the line to the aqualifter? What about the second outlet from the aqualifter?

 

[chesterthehero]

question never got answered. So How do i go about connecting the aqualifter to the overflow system?

do i replace the check valve with an airline into the same hole and the other end of the line to the aqualifter? What about the second outlet from the aqualifter?

yep... or you can leave the check valve there and use it as a connector.. the duckbill valves as well as the spring valves are both trash once they get wet once anyway.. which will always happen when sucking out bubbles however they make great connectors..