waynotcars
Aquarium Advice Regular
- Joined
- Sep 18, 2010
- Messages
- 79
Thanks for the confirmation Floyd. I'm ONLY trying to help. NOT prove how much I know. I've been in this hobby 42 years, since I was 10 years old, AND I am STILL learning every day!
Mag 12 and flow rate
- Thread starter Floyd R Turbo
- Start date
The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
mr_X
Aquarium Advice Addict
that's nonsense. it's the smallest point that is going to determine everything. if the smallest point is 1", then you can put a 3" pipe on it...it's still only going to put out what comes out of the outlet. it's definitely not going to increase what comes out of the outlet.
i don't care what danner says. it's a matter of physics.
i don't care what danner says. it's a matter of physics.
OP
OP
Floyd R Turbo
Aquarium Advice Addict
(edited)
I'm going to agree AND disagree with you here, because while from the outset that appears to be nonsense, there is definitely some other aspect of the physics of the Mag return pump to take into consideration, so they would not have made such a statement.
Why don't you call Danner and ask them. I couldn't get through to a tech person, but the person I did talk to said they had specifically had this discussion many, many times and the knew the answer right away, so it is a common question that they get.
I see where you are coming from, because as an engineer,I have MEs in my office that told me that your pipe flow rate is dependent on the smallest diameter pipe in the run. So it would make common sense to say the pump nozzle determines the hose size. However the pump output point may have slightly different properties because of backpressure requirements on the impeller and that pressure release after exiting the nozzle. If that pressure isn't eased, you get too much backpressure and your flow decreases.
Whatever the case may be, the answer, although not immediately logical, is clear from both manufacturer recommendation and from field experience - the pump output return hose needs to be 2x the ID of the output nozzle. Period.
It's just one of those things that you are going to have to prove to yourself by performing an experiment, or you are just going to have to accept it as fact and move on. Either way, it is what it is, and just stating that it 'cannot be true' or that it 'just doesn't make sense' does express your confusion/frustration - and believe me I share that with you - it doesn't matter unless you prove them wrong. And my guess is that you would find their statement to be correct or else why would they A) put it in their manual B) put it on the box C) tell people the same thing when they call in (it was their most common call, by the way). This is the conclusion I reached.
I'm going to agree AND disagree with you here, because while from the outset that appears to be nonsense, there is definitely some other aspect of the physics of the Mag return pump to take into consideration, so they would not have made such a statement.
Why don't you call Danner and ask them. I couldn't get through to a tech person, but the person I did talk to said they had specifically had this discussion many, many times and the knew the answer right away, so it is a common question that they get.
I see where you are coming from, because as an engineer,I have MEs in my office that told me that your pipe flow rate is dependent on the smallest diameter pipe in the run. So it would make common sense to say the pump nozzle determines the hose size. However the pump output point may have slightly different properties because of backpressure requirements on the impeller and that pressure release after exiting the nozzle. If that pressure isn't eased, you get too much backpressure and your flow decreases.
Whatever the case may be, the answer, although not immediately logical, is clear from both manufacturer recommendation and from field experience - the pump output return hose needs to be 2x the ID of the output nozzle. Period.
It's just one of those things that you are going to have to prove to yourself by performing an experiment, or you are just going to have to accept it as fact and move on. Either way, it is what it is, and just stating that it 'cannot be true' or that it 'just doesn't make sense' does express your confusion/frustration - and believe me I share that with you - it doesn't matter unless you prove them wrong. And my guess is that you would find their statement to be correct or else why would they A) put it in their manual B) put it on the box C) tell people the same thing when they call in (it was their most common call, by the way). This is the conclusion I reached.
Last edited:
OP
OP
Floyd R Turbo
Aquarium Advice Addict
Please lets keep this thread on the up and up. Name calling is inflammatory and unnecessary. My initial stance was the same as Mr. X so I understand his position, but I just ended up accepting what apparently is true based on what I've learned, whether it intuitively makes sense or not.
austinsdad
Aquarium Advice Addict
Everyone is gonna have to deal with this discussion, agree to disagree when needed, and keep the inflammatory remarks out of it.
Thanks all!
Thanks all!
Ziggy953
Aquarium Advice Addict
Personally I would go with the suggestion and recommendation of the company that makes the pump. Whether or not it makes sense to use 1.5" pipe or not if they say it is to be that way on their pump for max flow it's good enough. I say give it a try and see how your flow is. Better, kudos to them for good information, no change or worse, perhaps the pump is having issues and needs to be replaced or sent to them for testing and or repair.
