project5k
Reef enthusiast
yea, my job definately is getting in the way of my tank time... but, without it, i wouldnt have a tank so... whachya gonna do?
Tanked's 125 build thread
- Thread starter tankedchemist
- Start date
dcantucson
Reef pro
Clone yourself!
project5k
Reef enthusiast
oh if only i could...
tankedchemist
Reef enthusiast
I could clone a few of my cells... but that wouldn't help much, because my boss would just give me twice as much crap to do.
SO, I wentby the LFS yesterday just to get the tubing for my water change drain thing... and asked about the skimmer order I made. Turns out that the catalog listed the wrong pump (mag 12) and the manufacturer actually recommends an in-line (so, external) type pump. This would require my sump to be drilled for it.
Basically, the argument the manufacturer is making is that in-line pump have the impeller directly connected to the motor, so you don't get such a drastic decrease in gph as head height increases (compared to mags)... and I suppose that makes sense, but if the mag is rated for greater than the recommended gph at that specific head height... it's ok, right? In other words, the manufacturer says I need 1000 gph at 3' of head. THe mag 18 is rated for like 1200 gph at 3', so I figure... ok that'll work. but the guy says that he means 1000 gph with an in-line pump... in your opinion, is the manufacturer dude right? DO I have to pull the damn sump out of the stand and drill it, AND spend an extra $100 on a pump beyond what I planned?
SO, I wentby the LFS yesterday just to get the tubing for my water change drain thing... and asked about the skimmer order I made. Turns out that the catalog listed the wrong pump (mag 12) and the manufacturer actually recommends an in-line (so, external) type pump. This would require my sump to be drilled for it.
Basically, the argument the manufacturer is making is that in-line pump have the impeller directly connected to the motor, so you don't get such a drastic decrease in gph as head height increases (compared to mags)... and I suppose that makes sense, but if the mag is rated for greater than the recommended gph at that specific head height... it's ok, right? In other words, the manufacturer says I need 1000 gph at 3' of head. THe mag 18 is rated for like 1200 gph at 3', so I figure... ok that'll work. but the guy says that he means 1000 gph with an in-line pump... in your opinion, is the manufacturer dude right? DO I have to pull the damn sump out of the stand and drill it, AND spend an extra $100 on a pump beyond what I planned?
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project5k
Reef enthusiast
no. mag drive or direct drive isnt going to matter, if your talking gallons per hour vs head height, just go by how the pump is rated. the only thing is that with the pump your talking about, that extra flow could cause a problem so i would suggest putting a valve just after the pump so you have some control, but other than that, dont buy what he's sell'n cause its a bunch of BS!
Its pretty obvious that whoever told you that is a salesman, and not an engineer.
oh, and just as something that you can throw back at them, some of our submersable pumps can be run submersable or IN LINE and either way its still a magnetically driven impellor, and either way its ratings are still pretty valid as far as flow rates go(theres a tiny bit of loss using it inline vs submerged)
further more, if it were true that you have more losses per foot of head height on mag drive vs direct driven centrifugal pumps, then that would mean that the magneticly driven impellor would have to be slipping and i can assure you that this is not the case.
That would be called magnetic cogging, just like with a stepper motor. It would be a destructive and noisy occourence, and you would know when it happened.
Basically what would be happening, if this were to occour, would be that the impellor has a magnetic north, and south(or multiples of each) and inside the motor casing is a winding of wire, or multiple windings, these are called the fields, or coils. These are energized when you plug the pump in.
What happens is that the magnetic flux of north and south, that is generated by the coils or fields "rotate" around the impellor centerline due to the winding direction, # of windings, and the fact that you have plugged it into AC power.
This magnetic rotation, or commutation, pulls the magnetic rotor around in a circle around its central axis, same as the flux generated by the coil(s). The 2 are coupled, and rotate in a 1 to 1 ratio.
IF the impellor were to "SLIP" or cog, this would mean that the impellor would fall behind in its rotation enough degrees such that the impellor would basically slip or stall and fall behind untill the rotating magnetif flux catches up to it and tries to spin it again. This action is accompanied with a violent and sudden stop of the impellor, and thus is also accompanied by a noise.
Tell him hes full of it... you dont have to drill your sump, unless you just wanna... just use the bigger mag pump, put a valve on it for control, and smile, cause now you know more about how it works than he does.
Its pretty obvious that whoever told you that is a salesman, and not an engineer.
oh, and just as something that you can throw back at them, some of our submersable pumps can be run submersable or IN LINE and either way its still a magnetically driven impellor, and either way its ratings are still pretty valid as far as flow rates go(theres a tiny bit of loss using it inline vs submerged)
further more, if it were true that you have more losses per foot of head height on mag drive vs direct driven centrifugal pumps, then that would mean that the magneticly driven impellor would have to be slipping and i can assure you that this is not the case.
That would be called magnetic cogging, just like with a stepper motor. It would be a destructive and noisy occourence, and you would know when it happened.
Basically what would be happening, if this were to occour, would be that the impellor has a magnetic north, and south(or multiples of each) and inside the motor casing is a winding of wire, or multiple windings, these are called the fields, or coils. These are energized when you plug the pump in.
What happens is that the magnetic flux of north and south, that is generated by the coils or fields "rotate" around the impellor centerline due to the winding direction, # of windings, and the fact that you have plugged it into AC power.
This magnetic rotation, or commutation, pulls the magnetic rotor around in a circle around its central axis, same as the flux generated by the coil(s). The 2 are coupled, and rotate in a 1 to 1 ratio.
IF the impellor were to "SLIP" or cog, this would mean that the impellor would fall behind in its rotation enough degrees such that the impellor would basically slip or stall and fall behind untill the rotating magnetif flux catches up to it and tries to spin it again. This action is accompanied with a violent and sudden stop of the impellor, and thus is also accompanied by a noise.
Tell him hes full of it... you dont have to drill your sump, unless you just wanna... just use the bigger mag pump, put a valve on it for control, and smile, cause now you know more about how it works than he does.
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tankedchemist
Reef enthusiast
OK, I like your explanation much better. This is my extrapolation of what manufacturer said, so bear with me... Essentially I don't think his argument is that the impeller would dephase from the motor-- this cogging phenomenon, I think. I think what he's saying is, as you get back pressure from head, the magnetic impeller is more affected than a direct one would be so it goes slower... But like I said if the manufacturer says I need 1000 gph and its ratd at 1200 for that height...yeah. Glad I'm not the only one who thinks it's shit
The valve is a good idea tho. Thanks project
The valve is a good idea tho. Thanks project
yote
In Memoriam
HMMMM
And all this time I thought my Mag 12 was doin great.:D
And all this time I thought my Mag 12 was doin great.:D
tankedchemist
Reef enthusiast
what kind of skimmer do you have? I think this one is... bigger than I thought it would be. :p
project5k
Reef enthusiast
glad i could help :)
daugherty
part time reefer
what about this for a pump the rio 20hf does 990 at 4ft so it will be close to 1000gph at 3ft maybe a bit more but you can slow it down if needed. i use the 17hf for my DT tank ans it works great
tankedchemist
Reef enthusiast
I have had really bad experience with rio's... And I travel so much that I want something I really trust so I don't have to worry too much
tankedchemist
Reef enthusiast
Ok, so the damn thing is all plumbed. Took me from noon til 11pm. The bad news is, as I was gluing the very last drain pipe in, I accidentally cracked my first baffle. So now I'm pretty stumped... it's leaking slowly, but does that matter? opinions?
I want to get this filled asap... been waiting for months, and had the tank for 3 weeks... such slow progress!
I want to get this filled asap... been waiting for months, and had the tank for 3 weeks... such slow progress!
dcantucson
Reef pro
Better to fix it now instead of waiting until you have to. :(
Bifferwine
I am a girl
I don't think it matters. You will (theoretically) always have water flowing through the sump, so if it's leaking a little, who cares. And when you turn off the flow and water is not flowing through it, you will get water moving from one compartment to the other through the leak, so what? It's not like it will be leaking onto the floor.
yote
In Memoriam
I'm thinking along the same lines as Biff.It dont matter if a little water is leaking through a baffle.
project5k
Reef enthusiast
yea, i dont think a little leak through a baffel is a major issue, the water will be at about the same height on both sides of it most all the time anyway, so, unless you just really wanna replace it, i'd prolly fill it and forget it.
dcantucson
Reef pro
I think she will redo it. :lol:
tankedchemist
Reef enthusiast
Yote, biff and project were right... It has worked flawlessly all weekend despite my F-up... So I'm leaving it as is.
Normally you'd be right, David-- I'm a perfectionist. However, I am also not a handy person and plumbing this thing was brutally painful for me... So good enough will just have to suffice this time. :(
Semi-related, my elbow near the drain bulkhead has a slow leak...it's all glued in. Is there a way to fix it or do I just have to put up with it?
Normally you'd be right, David-- I'm a perfectionist. However, I am also not a handy person and plumbing this thing was brutally painful for me... So good enough will just have to suffice this time. :(
Semi-related, my elbow near the drain bulkhead has a slow leak...it's all glued in. Is there a way to fix it or do I just have to put up with it?
yote
In Memoriam
That I'd re-do.You dont want a drip inside the stand to start the wood rotting.
tankedchemist
Reef enthusiast
Ok, sooo... How do I get the glued bit off?
