Random Flow Generator- 3/4in RFG075 - Q&A

neoGeorge

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you may be able to attach genuine loc-line the stock fittings. it can be a bit hit and miss, but it does work sometimes. Then you can attach the 1/2in RFG to the loc-line.

A better option would be to use the our 19mm to 1/2in RFG slip-fit-drop adapters to attach the 1/2ub RFGs to the tank. if you want more ability to angle it, you can also attach 2 to 3 segments of Loc-Line to the drop adapters. However, you may not need it, since ehte RFGs will pulse/push flow in random directions at about a 30 degree angle from the tip of the nozzle.

The pump you have chosen should do really well with the dual 1/2in RFGs.
With that said, If after you get it setup, you want even more randomized flow, each 1/2in RFGs can easily handle as much flow as a single mightlyjet can create. The more flow you push through the RFG the more pronounced the randomized effect.

if additional questions, please let us know.
Thank you - I've posted this reply in my build thread so other JBJ tank owners can benefit from the answer.
 

brandon0921

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They do create some back pressure, as does any educator style nozzle. The RFG can create anywhere from 5% head loss at the lower end of our suggested flow rates to as much as 20% head loss when you go over our suggested Optimal flow rates.

With that said, the RFG nozzle does make up for that in terms of flow and water movement because of the way they work. Although they are not designed to work as an accelerator , they do draw in additional water volume through the educators and spread out the flow in such a way they move a larger volume of water than what is fed into it.

Hope that helps, and if you have any additional questions, please do not hesitate to ask.
I’m interested in one of these for a Reefer 350, but I’ve concerns over the back pressure as someone not educated on the topic.

Is back pressure at all damaging to a return pump? Could it possibly shorten the life of a pump or cause premature failure? Will the pump need to be run at a higher rate therefor consuming more electrictiry? Can back pressure create a siphon and potentially over flow a sump?

Thank you in advance. Only asking because I don’t know.
 
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Vivid Creative Aquatics

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I’m interested in one of these for a Reefer 350, but I’ve concerns over the back pressure as someone not educated on the topic.

Is back pressure at all damaging to a return pump? Could it possibly shorten the life of a pump or cause premature failure? Will the pump need to be run at a higher rate therefor consuming more electrictiry? Can back pressure create a siphon and potentially over flow a sump?

Thank you in advance. Only asking because I don’t know.
Hi Brandon,

Thanks for the questions.

Is back pressure at all damaging to a return pump? Could it possibly shorten the life of a pump or cause premature failure?
I would assume given enough back pressure it could be damaging to a pump, however, we have not had any reports of damage to pumps or experienced any damage in any of our testing.

With that said, the amount of back pressure the RFGs will create is directly related to the amount of flow you push through them. If you stay with in the "Suggested Optimal flow" rating for each of our nozzles, you should expect to see anywhere 10-15% additional head pressure at the top-end and less as you reduce the flow. If go being the Suggested Optimal flow, you get a bigger, more pronounced randomized effect, but at the expense of more head pressure, but in general is still well within the rating of most return pumps, so there is not reason it would prematurely shorten a pumps lifespan .

Will the pump need to be run at a higher rate therefor consuming more electricity?
It's also important to note, that all our Minimum and Suggests Optimal Flow rating are WITHOUT the RFG nozzle in place. So, if you need to hit a specific throughput for your sump/filtration, then yes, you may need to run the pump at a higher rate to achieve that after adding the RFGs. As far as electrical use goes, your DC pump will consume more electricity relative to what it might have with less head pressure. If however, you are using an AC pump, it will actually consume less electricity as you add more head pressure, since the pump is moving slower.

Can back pressure create a siphon and potentially over flow a sump?
Back pressure itself wont create the siphon, but you will want to pay attention to how deep your return lines are in your tank to insure the siphon breaks before it overflows your sump. The easiest way to figure this out is to calculate the gallons per in your display tank has and then compare that to the gallons per in your sump has in reserve.

You can calculate gallons per inch by multiplying length x Depth divided by 231. So, for instance if you have a tank that has a footprint of 72in x 18in, you would calculate the gallons per inch by
72 x 18 / 231 = 5.61

Then do the same for your sump, then multiply the result by the number of inches the water line is from the top of you sump while its running. This will give you your maximum reserve capacity.

Example: a 36 x 18 x 18in sump that has an average running water level of say 12in depth could be calculated like:

36 x 18 / 231 = 2.80 gallons per inch
18in total height - 12in water depth = 6in reserve

2.8 x 6 = 16 gallon reserve space.

Now you now approx how deep you can push your return line before overflowing your sump. I personally always reduce the maximum reserve by at least 10-15% just to be safe.

If your plan is to install RFGs, then this might help you figure out where to measure the siphon break in the display tank:
RFG Installation.jpg


Hope that (probably longer than it needed to be) explanation helped - LOL
if you have any addition questions, please do not hesitate to ask.
 
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brandon0921

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Thank you very much! I appreciate you taking the time to put that all down.

Hi Brandon,

Thanks for the questions.

Is back pressure at all damaging to a return pump? Could it possibly shorten the life of a pump or cause premature failure?
I would assume given enough back pressure it could be damaging to a pump, however, we have not had any reports of damage to pumps or experienced any damage in any of our testing.

With that said, the amount of back pressure the RFGs will create is directly related to the amount of flow you push through them. If you stay with in the "Suggested Optimal flow" rating for each of our nozzles, you should expect to see anywhere 10-15% additional head pressure at the top-end and less as you reduce the flow. If go being the Suggested Optimal flow, you get a bigger, more pronounced randomized effect, but at the expense of more head pressure, but in general is still well within the rating of most return pumps, so there is not reason it would prematurely shorten a pumps lifespan .

Will the pump need to be run at a higher rate therefor consuming more electricity?
It's also important to note, that all our Minimum and Suggests Optimal Flow rating are WITHOUT the RFG nozzle in place. So, if you need to hit a specific throughput for your sump/filtration, then yes, you may need to run the pump at a higher rate to achieve that after adding the RFGs. As far as electrical use goes, your DC pump will consume more electricity relative to what it might have with less head pressure. If however, you are using an AC pump, it will actually consume less electricity as you add more head pressure, since the pump is moving slower.

Can back pressure create a siphon and potentially over flow a sump?
Back pressure itself wont create the siphon, but you will want to pay attention to how deep your return lines are in your tank to ensure the siphon breaks before it overflows your sump. The easiest way to figure this out is to calculate the gallons per in your display tank has and then compare that to the gallons per in your sump has in reserve.

You can calculate gallons per inch by multiplying length x Depth divided by 231. So, for instance if you have a tank that has a footprint of 72in x 18in, you would calculate the gallons per inch by
72 x 18 / 231 = 5.61

Then do the same for your sump, then multiply the result by the number of inches the water line is from the top of you sump while its running. This will give you your maximum reserve capacity.

Example: a 36 x 18 x 18in sump that has an average running water level of say 12in depth could be calculated like:

36 x 18 / 231 = 2.80 gallons per inch
18in total height - 12in water depth = 6in reserve

2.8 x 6 = 16 gallon reserve space.

Now you now approx deep you can push your return line before overflowing your sump. I personally always reduce the maximum reserve by at least 10-15% just to be safe.

If you planning installing RFGs, then this might help you figure out where to measure the siphon break in the display tank:
RFG Installation.jpg


Hope that (probably longer than it needed to be) explanation help - LOL
if you have any addition questions, please do not hesitate to ask.
 

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