Cant figure out one problem with my VCA RFG

Mombo

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Got my new tank all setup with the RFG's. Love em!

Im having a problem with placement though. So first problem was I turned my pump off to do some work and realized they were going to siphon out a TON of water.

So I raised em a bit. Now they will randomly (as there name predicted) shoots water towards the surface and makes enough ripples that it will actually pull air into it and shoot micro bubbles all over the place as well as make a strange sucking sound.

Trying to figure out what people are doing.
 

kinetic

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Got my new tank all setup with the RFG's. Love em!

Im having a problem with placement though. So first problem was I turned my pump off to do some work and realized they were going to siphon out a TON of water.

So I raised em a bit. Now they will randomly (as there name predicted) shoots water towards the surface and makes enough ripples that it will actually pull air into it and shoot micro bubbles all over the place as well as make a strange sucking sound.

Trying to figure out what people are doing.

I had the same issue with mine. It would suck in air because the nozzle is too close to the surface and creates a vortex. I actually was never able to fix this issue. I know some people added segments of locline to push the nozzle further away from the surface of the water. So you might just have to keep the nozzle dipped down.

Behind the nozzle opening are the slots that should break the siphon at some point?

My pump is a DC pump (Reef Octopus VarioS-4) and I actually set it to only 8% power during feeding and light maintenance to keep the water at a standstill in the return drain, so it doesn't siphon. I did this by connecting it to my Apex Jr. with a VDM module. It's really nice, because the water level never drops.
 

Vivid Creative Aquatics

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Got my new tank all setup with the RFG's. Love em!

Im having a problem with placement though. So first problem was I turned my pump off to do some work and realized they were going to siphon out a TON of water.

So I raised em a bit. Now they will randomly (as there name predicted) shoots water towards the surface and makes enough ripples that it will actually pull air into it and shoot micro bubbles all over the place as well as make a strange sucking sound.

Trying to figure out what people are doing.

@Mombo I should be able to help with this. Can you give me a bit more detail

- What size RFGs are you running?
- Approx how much flow (GPH) are you pushing through them?
- What size/type tank? Is it an All-in one, if so, what brand?
- If possible, can you post a pic of the nozzle installed from the side. I would like to get a better idea of how they are installed now.

Thank you!
 
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Mombo

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I think I am making some progress. Ive been tuning my return pump flow down a bit and it has made the suction go away. So I could raise it a bit and now it doesn't over siphon the tank. Does the suction a little bit still now but I think I just to tune it a bit more.

Its a 120g SCA tank wtih 2 x 1/2in RFG's on it. I think I am pushing about 900gph through it now.
 

Vivid Creative Aquatics

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I think I am making some progress. Ive been tuning my return pump flow down a bit and it has made the suction go away. So I could raise it a bit and now it doesn't over siphon the tank. Does the suction a little bit still now but I think I just to tune it a bit more.

Its a 120g SCA tank wtih 2 x 1/2in RFG's on it. I think I am pushing about 900gph through it now.
OK cool - is 900gph per nozzle or 900GPH for both - so aprox 450 each.

I'm going to setup it up on our Demo tank and run some tests so I can give you specific GPH and depths.
 
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Mombo

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450 per nozzle. That is an estimate. I’m running a jebao 6500 at 60%. It does 1730gph at full power so at 60% it’s around 1000. Then it has about 5ft of 1in pipe and 2 elbows before it gets to a T pipe and goes down to 2x 1/2in nozzles. So I was guessing between 800 and 900 gph after all of that.

Could be less I’m not sure how to calculate all of that stuff
 

Vivid Creative Aquatics

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450 per nozzle. That is an estimate. I’m running a jebao 6500 at 60%. It does 1730gph at full power so at 60% it’s around 1000. Then it has about 5ft of 1in pipe and 2 elbows before it gets to a T pipe and goes down to 2x 1/2in nozzles. So I was guessing between 800 and 900 gph after all of that.

Could be less I’m not sure how to calculate all of that stuff

Your calculations are close enough. :)

I ran some tests and at ~450gph and it looks like you should be able to get the base of the nozzle body (where the educators are located) to within about 1/2in of the surface of the water and have it not suck air. This of course may be effected if you have a wave maker in your system and the water level rises and lowers with the standing wave.

The syphon will break at approx. 3/4in where the accelerator portion of the nozzle is

The SCA 120 I looked up has dimensions of 48 x 24, so if we do the math, 48 x24 / 212, it looks like you have about 5.4 gallons per inch which puts this at about ~4gallons of water back into the sump when the main return pump is shut off. Depending on how big your sump is, they may or may not be an issue.

The lower the GPH the closer you can move those nozzles to the surface. Also - to help minimize the splashing you can point them down bit. The stream will exite the nozzle at about a 3o deg angles. So, if point them down about 20 degrees, then you still get surface agitation, but no splashing.

hope that helps and keep us posted as to your progress.

here are a few shots I took during the test

RFG050_0536.jpg



RFG050_0535.jpg
 
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Mombo

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Thanks for all the help on this. I think ive got it figured out now. Once I tuned my return pump to the proper flow for my sump it was much easier to get everything set up correctly.
 

Vivid Creative Aquatics

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Thanks for all the help on this. I think ive got it figured out now. Once I tuned my return pump to the proper flow for my sump it was much easier to get everything set up correctly.
Great! glad I was able to help. Be sure to post a pic of you tank when you get a chance to the RFG show-off thread :)
 

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