# restricting water flow on a Marineland C-360



## Midnighttide102 (Oct 2, 2014)

Best way to get the flow to not be as strong but still have the same flow is drill bigger holes in your spray bar it won't be as powerful


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## FatherLandDescendant (Jul 24, 2014)

Pull up on the cutoff lever (the first lever you pull up on when disconnecting the valve block from the head), not all the way but enough to restrict the flow while it's running. Just don't unlock and try disconnecting the block from the head unless you finish closing that valve or you'll siphon drain your tank when you release the block.


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## Bryanmc1988 (Apr 3, 2012)

FatherLandDescendant said:


> Pull up on the cutoff lever (the first lever you pull up on when disconnecting the valve block from the head), not all the way but enough to restrict the flow while it's running. Just don't unlock and try disconnecting the block from the head unless you finish closing that valve or you'll siphon drain your tank when you release the block.


Will doing this damage the filter motor? I plan on doing this but have no idea if it will have any effect on the filter damage down the road or not...

With this filter it has 2 lever, the fist is a big lever to shut off the flow even if it's pulled all the way up to shut off the flow, it doesn't pop off the lock as there is a smaller lever under this to unlock the barb for removing...


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## FatherLandDescendant (Jul 24, 2014)

Bryanmc1988 said:


> Will doing this damage the filter motor? I plan on doing this but have no idea if it will have any effect on the filter damage down the road or not...
> 
> With this filter it has 2 lever, the fist is a big lever to shut off the flow even if it's pulled all the way up to shut off the flow, it doesn't pop off the lock as there is a smaller lever under this to unlock the barb for removing...


Restricting the flow on any canister filter causes the motor to work harder than unrestricted flow. That being said yes it does shorten the life expectancy of a unit, how much is anybodies guess though IMHO it is minimal and not something I personally worry about on the C220 model I do this to on a 29gal tank I have. I use the factory cut off (the first lever) to restrict the flow on my unit.

Another way to decrease the velocity of the water return without restricting the overall flow of the unit would be to install a spray bar either a DIY or some other aftermarket brand as Marineland doesn't offer one for their filters. If the flow is to strong with a spray bar you can then enlarge the holes in the bar to decrease velocity of the water.


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## Linwood (Jun 19, 2014)

I agree on the spray bar solution, but....



FatherLandDescendant said:


> Restricting the flow on any canister filter causes the motor to work harder than unrestricted flow. That being said yes it does shorten the life expectancy of a unit, how much is anybodies guess though IMHO it is minimal and not something I personally worry about


I read this all the time on forums (work harder, and not good for it), but I cannot find any concrete evidence to support it. I even rigged up a test bed once and did current flow tests at various flow rates, and actually found LESS current flow (really something of a definition of how hard it works) with the flow completely stopped. That was on a pond pump, when I get a few minutes I'll do it on a canister (I now have one rigged with a ball valve to adjust flow for a small shrimp tank and a big canister). 

Now completely stopping the flow will prevent water from cooling the pump area, and might cause overheating. But water has such a huge heat capacity that it takes very little flow to cool. 

I am not saying I am absolutely certain that no harm is done... just I can find neither theory nor any practical evidence to support it being harmful. But I'd love to see some science on the subject.


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## FatherLandDescendant (Jul 24, 2014)

Linwood said:


> I agree on the spray bar solution, but....
> 
> 
> 
> ...


When you restrict the flow with a cutoff valve the motor is still trying to move the same volume of water as when it is unrestricted. This puts back pressure on the motor, or what could also be called increasing the load the motor tries to carry AKA loading. It makes the motor work harder and because it can not expend its' energy fully its' temperature increases. Heat release from a motor is unused energy, this is a basic engineering principle any mechanical associates degree holder can attest to, they use to teach it in public school but those days are long gone now.

Unlike a pond pump, which I assume what you are referring to is either a submerged unit or a throughput unit, a canisters motor does not have the benefit of being "liquid cooled". Water in the C series filter doesn't flow anywhere close to the motor windings, I have had the head unit on one of my two C220 apart. The motor is about 3" cubed, sits above the outflow channel, and by far the largest amount of the coil doesn't contact the water channel.

Heat buildup is what kills these motors, I might suggest that if/when you do your experiment you take heat measurements of the motor area of the head from idle, unrestricted, and restricted. I'd be real interested in your findings. In fact it's about time to clean the filter on my C220 restricted filter, I'll take some temp readings of it tomorrow with an IR temp gun and report those findings in this thread. While I'm at it, and since I really should reinstall those screws:redface: I'll snap some photos of what the inside of the head looks like so you can see why water flow, even minimal flow, doesn't affect cooling in regards to these motors.

Mean while here are a few articles related to heat buildup in electric motors.

https://www.progress-energy.com/assets/www/docs/business/motor-protection-voltage-unbalance.pdf

http://franklinaid.com/2012/02/15/why-motors-fail-part-1/

http://electrical.about.com/od/wiringcircuitry/a/thermalprotectionformotors.htm

As an after thought, you could in theory restrict the water flow AND extend the motor life by wiring a current reducing switch to the motor. All it would take is a dimmer switch for lighting. It would restrict the electrical current to the motor lowering its' RPMs and thereby reduce the final output rating.


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## Linwood (Jun 19, 2014)

FatherLandDescendant said:


> When you restrict the flow with a cutoff valve the motor is still trying to move the same volume of water as when it is unrestricted. This puts back pressure on the motor, or what could also be called increasing the load the motor tries to carry AKA loading. It makes the motor work harder and because it can not expend its' energy fully its' temperature increases. Heat release from a motor is unused energy, this is a basic engineering principle any mechanical associates degree holder can attest to, they use to teach it in public school but those days are long gone now.


I don't have an associates degree, so I guess I'm going to have to figure it out now, rather than just knowing the answers. 

If I get some time tomorrow will also take some readings. You may be exactly correct, but ... maybe not. Remember, these are not the kind of motors your links describe, really. The typical electric motor we are familiar with will increase current consumption as load increases, because they typically have implicit or explicit feedback mechanisms that are not present in the same way in these simple permanent magnet motors. 

More tomorrow. Or if I run into anyone with an associates degree I'll just ask them. :hihi:


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## Aquadawg (Aug 18, 2012)

Enlarge the holes in the spray bar. Just use a larger drill bit than the holes in your spray bar; let it run for a day then adjust again if necessary. Continue until you have the flow you want. This will not harm the motor in any way.


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## FatherLandDescendant (Jul 24, 2014)

Linwood said:


> Remember, these are not the kind of motors your links describe, really.


Sure they are, just on a smaller scale


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## Clear Water (Sep 20, 2014)

I have restrict the flow of pumps on the return side and have never had an issues. They were external pumps and not a canister. The plumbing guy I use for advise tells me if you have to slow flow down it should be on the return side of the pump not the inlet.


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## Linwood (Jun 19, 2014)

For curiousity I took a SunSun 404B canister filter and did some experimentation. I measured rms amps through the device with a regular meter, and temperature at the hottest point on the surface with a thermocouple. 

I adjusted flow between 0 and 100% with a ball valve on the output (as Clear Water points out, you would never throttle input for noise reasons). I guessed at the 10% and 50% point based on watching water disturbance, the 0% and 100% of course were actual. I let it settle about 15 minutes after the change before taking the reading each time.


```
Flow     Amps    Temp(F)
0%      0.739    89.1
10%     0.744    89.1
50%     0.739    89.5
100%    0.734    89.7
```
To me these are pretty much "no change". The temp readings are with a pretty accurate and quite precise device however measuring it on the exterior plastic surface subject to airflow, etc. is going to make it fairly imprecise. I doubt the trend of rising temperature is real (especially since it is counter intuitive); I think it is safe however to say there was no significant temperature rise.

The amperage measurement showed ongoing fluctuation during the measurement period, probably due to voltage fluctuation of the house current. An eyeball estimate would put the variation of that as being comparable to the differences in individual data points. But I think it is fair to say as well that there is no significant current flow difference over the range of flow. 

I did not leave the flow off for more than about 15 minutes. I would guess that over long periods that temperature may rise a bit more, transferring more heat to the water in the canister. Enough to damage? Not sure, but certainly not over short periods, and besides -- turning flow entirely off is pointless as an operating mode.

I should note as well the approximate 10w UV was on during these times as well, so the amperage is a bit higher that just the pump, but it would be an equal effect on each one.

It's hard to prove a negative (that an operating mode does no damage), but for this canister I can see no signs of anything that can cause such damage. It's dangerous to extend that to every canister everywhere but... all the ones I've looked at are about the same in general pump structure.

I also looked in the user manuals for a few filters (including Marineland) and could not find where any recommended against throttling.


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## FatherLandDescendant (Jul 24, 2014)

Linwood said:


> For curiousity I took a SunSun 404B canister filter and did some experimentation. I measured rms amps through the device with a regular meter, and temperature at the hottest point on the surface with a thermocouple.
> 
> I adjusted flow between 0 and 100% with a ball valve on the output (as Clear Water points out, you would never throttle input for noise reasons). I guessed at the 10% and 50% point based on watching water disturbance, the 0% and 100% of course were actual. I let it settle about 15 minutes after the change before taking the reading each time.
> 
> ...


My findings run pretty much along the same lines, however I didn't measure amperage, however restricting the flow won't cause an amperage change though heat buildup could and most likely would.

Though I didn't run mine with the flow cut 100%, I did a full open and a roughly 50% restriction of course measuring the plastic case, running each for 1 hour. I may one day run it without the screws in the top shell just so I can measure the actual motor.

Anywho, ambient room temp is 69 at unrestricted flow mine runs 88.3 degrees, restricted 89.4 degrees. But as you said this is measuring through the case. When I first shut the filter down I took the top shell off and the motor was 104.2 degrees.

None the less even at those temps the shellack they use to insulate the field coils on the motor wouldn't suffer from heat damage, you'd have to run temps in the 140 to 150 degree range for extended periods.

Oh yea BTW, I can only speak for the ML C series filters but you mentioned perma magnet motors, the motor in the C series isn't a perma magnet motor, looks more like a field coil motor to me, but have a look.


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## Linwood (Jun 19, 2014)

FatherLandDescendant said:


> None the less even at those temps the shellack they use to insulate the field coils on the motor wouldn't suffer from heat damage, you'd have to run temps in the 140 to 150 degree range for extended periods.
> 
> Oh yea BTW, I can only speak for the ML C series filters but you mentioned perma magnet motors, the motor in the C series isn't a perma magnet motor, looks more like a field coil motor to me, but have a look.


I think that's C not F -- a typical electric motor tends to run well over 100C internally. My guess is that the most likely-to-be-damaged item is the plastic case, not the wiring, if it over heats. The plastic, now, probably will start to deform at your temperatures, so I agree regardless, including being nowhere near it.

The picture -- can't tell. In both of mine (Fluval and SunSun) the motor is hidden away and the impeller exposed. I may be able to disassemble it, haven't tried. But you saw the same kind of behavior so even if different, I think it's still a reasonable assumption that flow throttling does not appear to be harmful to it.


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## FatherLandDescendant (Jul 24, 2014)

Linwood said:


> I think that's C not F


My temps are in F, tis what I have the temp gun set at 



Linwood said:


> I think it's still a reasonable assumption that flow throttling does not appear to be harmful to it.


Agreed:thumbsup:


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## Linwood (Jun 19, 2014)

FatherLandDescendant said:


> My temps are in F, tis what I have the temp gun set at


I meant you guess at the 140 range to damage the insulation on the wire.


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## PlantedRich (Jul 21, 2010)

Just a simple thought but if flow stopping ruined motors, wouldn't we hear lots of noise from the folks who come home and find their filters have not restarted after a short power failure? Think how many times we debate whether filters should have to be bumped to restart them. If all those folks were losing a filter every time, I'm thinking they would squall a bit louder than they do. And then there are the folks who walk away and forget to open ALL the valves. 
I find that when a big chunk of something works it's way to the impeller and winds up stopping it-- it hurts nothing. It used to happen fairly often when I ran a Cascade 1000 as it would bypass a full grown horse!


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## FatherLandDescendant (Jul 24, 2014)

Linwood said:


> I meant you guess at the 140 range to damage the insulation on the wire.


Prolonged exposure to high temps delaminates the insulation on the wiring and allows it to flak away. 



PlantedRich said:


> Just a simple thought but if flow stopping ruined motors,


The discussion isn't about it ruining motors right away, but about the theory that restricting water flow shortens the over all life expectancy of a filters motor.


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## PlantedRich (Jul 21, 2010)

Quote: The discussion isn't about it ruining motors right away, but about the theory that restricting water flow shortens the over all life expectancy of a filters motor. 
__________________
I know what your part of the discussion was about but it is a pretty silly premise as some filters come with the recommendation to close the cutoff part way. 
Too much theory and not enough looking at facts?


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## FatherLandDescendant (Jul 24, 2014)

PlantedRich said:


> Too much theory and not enough looking at facts?


This is a discussion board, we were discussing.


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