crazyelece
Fish Addict
A 1" drain will handle up to 600 gph drain rate so the mag 7 is fine by itself without a bypass. It also a mag drive so it won't be effected by back pressure like other pumps. Extra head does not add wear to the pump.
Finally Made Up My Mind....
- Thread starter Siamese Fighter05
- Start date
andywg
Bored into leaving
I may be being thick here, but don't all pumps work on the motor principle of having magnets and an electrical current to create motion? (all at right angles if Faraday's Left hand theorem still works). Surely all electrical pumps are magnetic driven?
And all pumps will be affected by back pressure, it might not create too much wear and tear when it is due to head (which is a bit different to having a valve restricting the flow so close to the pump) that is why they pump slower as the height increases.
And all pumps will be affected by back pressure, it might not create too much wear and tear when it is due to head (which is a bit different to having a valve restricting the flow so close to the pump) that is why they pump slower as the height increases.
Siamese Fighter05
Fish Herder
So the Mag 7 will give me a flow rate of just over 6X per hour. Is there any reason why the reccomended flow rate is 5X in the sump? And would 6X still be okay?
Thanks
Andy - I thought so too
crazyelece
Fish Addict
That flow rate worked fine in both my sumps. One was for a 30 gal and one was for a 120 gal. I don't think flow rate through the sump has much to do with anything as long as the water is in there long enough to get filtered.
There are vast differences between different types of pumps. All pumps are based on some sort of motor design. Some have a specific motor that he pump is attached to (like the external type similar to pool pumps) others are a sealed system that need to be submerged to stay cool and yet others can be run both inline and submersible. The details are really too much to get into for this thread.
The way a mag drive like danner's mag series work is a sealed secton that generates a magnetic field in its core. A magnet (two of them actually) are in this core fixed to a center pin. The impeller for the pump is also attached to this pin. As the field is generated the magnets rotate and so does the pin and impeller. This type of system spins at the same rate no matter what. It will be able to pump a certain head height and then the water pressure backs up and the pump pressure can't compete. The impeller never slows down or stops spinning. This is why this type of pump doesn't get affected by head pressure. Other pumps that slow or physically stop with back pressure are the type that get affected by too much back pressure or head. Yes the impeller wears as do all pump impellers. The bad effect of head actually damages the electrical or motor portion of pumps, just not ones like the mag series.
Now as for a ball valve, why do you think a ball valve is bad for any pump? All a ball valve does is add head to the pump. From the pumps perspective it is the same as if the plumbing was longer or higher. Again this does not affect the mag series pumps. This is the main reason I like these pumps. Their only down side is they seem to have leaking issue when used as an inline pump.
There are vast differences between different types of pumps. All pumps are based on some sort of motor design. Some have a specific motor that he pump is attached to (like the external type similar to pool pumps) others are a sealed system that need to be submerged to stay cool and yet others can be run both inline and submersible. The details are really too much to get into for this thread.
The way a mag drive like danner's mag series work is a sealed secton that generates a magnetic field in its core. A magnet (two of them actually) are in this core fixed to a center pin. The impeller for the pump is also attached to this pin. As the field is generated the magnets rotate and so does the pin and impeller. This type of system spins at the same rate no matter what. It will be able to pump a certain head height and then the water pressure backs up and the pump pressure can't compete. The impeller never slows down or stops spinning. This is why this type of pump doesn't get affected by head pressure. Other pumps that slow or physically stop with back pressure are the type that get affected by too much back pressure or head. Yes the impeller wears as do all pump impellers. The bad effect of head actually damages the electrical or motor portion of pumps, just not ones like the mag series.
Now as for a ball valve, why do you think a ball valve is bad for any pump? All a ball valve does is add head to the pump. From the pumps perspective it is the same as if the plumbing was longer or higher. Again this does not affect the mag series pumps. This is the main reason I like these pumps. Their only down side is they seem to have leaking issue when used as an inline pump.
You got that right... I have a Mag 5 watercooling my computer, and it was a PAIN to seal the main O-ring.
Your point about head not affecting the pump is mostly true. Increasing head pressures will not damage the impeller or the impeller housing because as you say, the impeller always spins at an RPM dictated by the size of the magnets in the drive. The head capabilities are then a function of the efficiency of the impeller design and the power of the magnets. HOWEVER, there are 2 drawbacks to running high head on magdrive pumps. The first, is heat. However if the pump is submerged instead of inline this is not much of an issue. In my computer for instance I need to have water flowing over the pump, but in the tank, no big deal.
The second downfall is electron migration and magnetic deteriation over time. While the impeller speed remains the same during high and low head operations, the current drawn by th emagnets increases dramatically in magdrive pumps when the head pressure is increased. Thats the reason for the heat increase as well. But when the magnets themselves are drawing more current, they will loose capacity and lifespan faster than when drawing low current. IUts impossible to give a true estimation, but a magdrive pump operating at 0 head, 24/7 could last 20 years. And one operating at full head might only last 5-10 years before the magnets hve deteriorated. Please dont take that as gospel, but you get the idea.
Back to SF05's specific issues, let me say that I'm running a mag 7 with a mere 1/2" drain (wouldn't reccomend this) with no problems. Now my head losses are pretty substantial since my tank is so flippin tall, and I run some recirc into my sump cause my return line blows water over the edge of my tank if its full on, but it works great for me. I too would reccomend a mag 5 or 7 for a first-time sump designer. I also would reccomend GREATLY searching for them online. Dunno what its like around where you are, but I can order a Mag 7 for $55 shipped, and my LFS charges $90 for them
you do the math Siamese Fighter05
Fish Herder
Wow Thanks alot for all that info guys, that's cleared up alot of questions and i'll get looking for the best deals on the mag 7. I haven't found one yet so i don't know if they are available in the UK.
Might have to order from the US
Thanks again
Dan
Might have to order from the US
Thanks again
Dan
Siamese Fighter05
Fish Herder
What dimensions should i use for the overflow box, i want it to do good surface skimming but not be too noticable.
I get what everyone is saying, but T'ing off back into the sump and putting a valve on the T will not have any effect on a pumps life. All it is doing is allowing the flow to be reduced back upto your tank.
If the valve is shut, it pumps up the head height from your sump to your tank. if its open slightly it reudces the flow upto your tank as the water will take the easiest route back into sump, so reduces the head height.
Using a valve in that way will have no detrimental effect on your pump and allow you to fine tune your flow if you find its too much. Also allow you to use a bigger pump and underwork it.
If the valve is shut, it pumps up the head height from your sump to your tank. if its open slightly it reudces the flow upto your tank as the water will take the easiest route back into sump, so reduces the head height.
Using a valve in that way will have no detrimental effect on your pump and allow you to fine tune your flow if you find its too much. Also allow you to use a bigger pump and underwork it.
Siamese Fighter05
Fish Herder
I see what your saying i guess it would be beneficial to add it and if i don't need it i can just shut off the valve 
Any thoughts on overflow box size?
Any thoughts on overflow box size?
Matthew5664
Fish Herder
Can I but in here>>> puting a ball vale in may not have a detrimental effect on the pump but what a wast of power! I'd (and have) go with the T option back to the sump or T at the top of the tank and have a second outlet. atlest use the power generated by the pump!
As for the overflow 12cm wide 2cm gap with a 7cm drop into the tank and a 10cm drop over the tanks back would work. I think the idea is to have more of a drop at the back that the front to create the suck to pull the water up the first bit of the overflow. as for how wide the gap is I'd keep it the same. And for the width, this is where you calculate the ammout of flow you want.
Please don't take my word for it but thats my thoughts on the subject.
OOoooooo...... nearly forgot try THIS for the overflow.
good luck
As for the overflow 12cm wide 2cm gap with a 7cm drop into the tank and a 10cm drop over the tanks back would work. I think the idea is to have more of a drop at the back that the front to create the suck to pull the water up the first bit of the overflow. as for how wide the gap is I'd keep it the same. And for the width, this is where you calculate the ammout of flow you want.
Please don't take my word for it but thats my thoughts on the subject.
OOoooooo...... nearly forgot try THIS for the overflow.
good luck
AGREED
As for the overflow, are you drilling or not? Not sure what your final decision was...
Maybe Matt wasn't clear. T's = good. Outlet restricting valves = bad
Siamese Fighter05
Fish Herder
Thanks for the help guys....
Matt - I'm not using that type of overflow as it is even more complicated than the one i prefer (Well it is to me anyway
) Heres the one i'm using:
Looks okay everyone? Just need to decide on box size.
Matt - I'm not using that type of overflow as it is even more complicated than the one i prefer (Well it is to me anyway
) Heres the one i'm using:
Looks okay everyone? Just need to decide on box size.
That overflow is what im using (same size tank as well i think, 36x15x12 ??)
i drew a crude picture just to clear up what i mean about a valve that will have no negative effect on a pump and allow you to fine tune if you find the pump is too powerfull for your overflow and it allows you to feed other things so nothing is wasted. The same querstion has been asked many many times and answered this way (not on this forum)
if still not understood we'll agree to disagree and stay on topic.
(same size tank as well i think, 36x15x12 ??) i drew a crude picture just to clear up what i mean about a valve that will have no negative effect on a pump and allow you to fine tune if you find the pump is too powerfull for your overflow and it allows you to feed other things so nothing is wasted. The same querstion has been asked many many times and answered this way (not on this forum)
if still not understood we'll agree to disagree and stay on topic.
Similar threads
Most reactions
-
295 -
220 -
214 -
184 -
172 -
167 -
149 -
136 -
135 -
125 -
118 -
109 -
105 -
95 -
94