Sump sound issues

[jerome736]

Hi guys,

I wasn't sure which forum to stick this in, so I thought the DIY forum sounded appropriate and I'd try my luck here.

I just set up my new tank in the apartment I recently moved too. All my livestock, etc was transferred from my old smaller tank. I've never run a plumbed tank before, so this is my first time doing all this. My tank is 36"x24"x18" and the water drains from an external overflow with 1" bulkheads and a herbie setup. My overflow is pretty quiet after I tuned it with the ball valve, but I'm still getting a lot of splash from water flow within my sump. I put some filter floss in an area to reduce some of the splash and its helped some, but I'm looking for a more permanent solution. The splash occurs when water transfer from one "compartment" to the next. I'm using a Eheim 1262 for my return pump and I'm having a low rumble/vibration noise coming from it, so I'm looking for a way to pad this to reduce its noise as well. Any help or suggestions would be appreciated!

[GIJOE007]

can you post a pic of your sump set up so we can see what the problem might be?

[reef_only]

A pic would help; as my best guess on your problem that you can resolve by submerging the overflow pipe to your sump, this will reduce the bubble and noise. Make sure your overflow has some air escape when doing submerge.

[Pbrown3701]

You may have too much flow going through your sump.

If the cause of the noise is the "waterfall" effect over a sump baffle, then you can make a short "ramp" that allows the water to flow down more gently into the next section. Be sure you don't make an air pocket underneath though as you don't want to trap stagnant air. just silicone in a piece of cut acrylic or glass that is the correct width. You can leave the crack between the "ramp" and the baffle unsealed so air can escape.

Just an idea.

[jerome736]

The sound isn't really coming from the overflows (I already have the ends submerged into the sump)

I'm stuck at work right now, I'll post a picture later when I get a chance. I know off the bat that the design of the sump isn't too great, and yeah, its the waterfall noise.

I was thinking about reducing the flow of the return with a ball valve on the return. Would this cause any deleterious effects?

I was also considering adding a check valve on my return as my sump is unable to handle the amount of water that would drain out of the tank in the event of a power outage. Would this restrict flow at all?

Thanks!

[GIJOE007]

adding a ball valve on your return is a must!!! The ball valve on your retrun will ultimatly determine how many gph turn over you have on your system.

I have a check valve on my retrun due to the fact that my 1" bulkhead is drilled directly in the center of my back pane. If the power goes out, the check valve will shut off any water from coming back in to my sump. The only thing is with check valves, is that you have to test and replace every so often due to the fact that coraline and such may restrict the float in the check valve. If this happens the check valve will fail and water will drain until it reachs the lowest bulkhead in your display. The arrangement I have is return pump, check valve, ball valve. I used a 1 1/4" check valve so that I can reduce the amount of restriction and ultimatly have less head pressure. I also have threaded reduceres going from 1" to 1 1/4" so that I can unscrew the assembly and performe maintanence on my check valve. I also perform simulated "power outages" to ensure the check valve is still operating 100% (once a month).

Post a pic of your sump when you can and hopefully we can help figure this issue out.

Hope this helps.

[reef_only]

I don't use check valve; I think it's just me I couldn't have good sleep with check valve, always think of its malfunction.

[Pbrown3701]

check valves WILL fail and according to Murphy's Law, will fail at the most inopportune time (Christmas Eve or the like). It's not a good way to do things (however it's better than nothing as you have now...yikes!).

The best way to do it is to set the system up and leave the return pump off. Fill the main tank allowing excess water to drain to the sump until the sump is full. Once the sump is full, turn on the main pump. The water level in your sump will drop to the "normal operating line." I mark this line with a Sharpie. Now, so long as the water level doesn't go above that line when the return pump is on, there is no way you can have a flood.

My sump runs about 1/4 full.

Also, throttling back your return pump will not hurt anything. In fact, it will allow the pump to run cooler as it is doing less work. It will also cause the pump to use less power thus reducing your electric bill. Just be sure you restrict the OUTPUT of the pump and not the suction side. In other words, you want to put back pressure on the pump, not starve it of water.

One last point, it's better to get your flow in the tank via powerheads or a closed loop system rather than running high flow through your sump. If you're using a recirculating skimmer in-sump, then you really only need about 5-10 times your total water volume per hour through the sump (depending on stocking). If you have a single pass skimmer, you should have slightly higher volume through the sump (maybe 15 to 20 times) for maximum efficiency.

[Doahh]

Reef Myth number 3:
" In fact, it will allow the pump to run cooler as it is doing less work. It will also cause the pump to use less power thus reducing your electric bill."
False.
The pump works harder because it has to work through a smaller hole... it's like putting your thumb over the end of a hose.
It puts a lot of strain on the pump and could make it fail early

[Pbrown3701]

Doahh, sorry, but your wrong on that point.

[Kewlworm]

Doahh is right cause the pump won't "slow down" just because you restricted the output, the pump will still pump. The back pressure actually would make the pump work harder to "force" that water out thru that restricted return line.

Then again I am not an expert, so a friendly correction are welcome.

[Pbrown3701]

bHp=QxHxSG/3960e

Where
bHp is the break horse power of the motor
Q is the flowrate in GPM
H is the head (or pressure) in ft.
SG is the specific gravity of the fluid
e is efficiency

Now look at any radial centrifugal pump curve and choose two points along the pumps opperation curve. plug in the numbers and you will see that the Hp or power of the pump decreases with decreased flow.

Also, you can look up centrifugal pump bhp curves and see that bHp increases with increased flowrate.

[Doahh]

All of your math will do nothing...
Take a standard Kill-O-Watt and plug it in. Mag 7 is pulling 60-70 watts
Restrict the flow and that wattage figure WILL go up

[Gold Stripe]

I'm just a novice when it comes to pumps but most are mag drive right? So increased pressure isnt going to slow the motor down any, its just going to slow the impeller down and creat more friction which will increase heat which will reduce efficiency and increase wear. I would think restricting a pump a small amount would be ok but any significant restriction would be the same as using an undersized pump in that the pump will have to work harder to try and turn the impeller and thus cause premature failure. Just my .02

[Pbrown3701]

There are certain pumps where you may get a very slight increase in power by restricting the output over a VERY NARROW band of it's performance curve (typically towards it's maximum capacity). That would be an exception to the rule however.

I'm not saying it's intuitive, but it IS REALITY. The power is directly proportional to the flowrate. Restricting the output (or putting more head on the pump) decreases the flowrate and thus, decreases the power consumption.

Look here:

if you notice the green dotted lines, those are lines of constant power (contour lines). The pump must operate on its performance line (the black lines that go generally down left to right). So pick an impeller size and follow that line down. You will see that as the flowrate increases, you will pass HP lines that increase. This means that as flowrate increases, you need MORE POWER to run the pump.

These graphs are a little confusing if you haven't had to use them before, but it's all right there.

You will notice towards the far right side of the performance curve for the pump, that the line bends down. This very small section of the performance curve is the only area where you might require more power (on some pumps- not this one) initially. But if you were to continue to restrict, you would decrease the power.

One final concept for Gold Stripe - have you ever been SCUBA diving? if so, when you are at depth and the pressure if quite high, is it any harder to swim? The answer is no. Pressure alone does not cause a body to have to do more work to move through it. IT's much more complicated than that.

[Pbrown3701]

http://www.zoeller.com/Zep/Techbrief/JF1article.htm

See here and notice the "MOTOR INPUT" line which corresponds the the Y axis on the right. THis is the power required by the motor. You will see that it increases as flowrate increases.

On SOME pumps, at the far right side of the graph, that power line will tail off to level or even decrease slightly. My guess is that is what Doahh is seeing with his Mag7 in the bathtub experiment. FYI - it's not good to run a pump in that part of it's performance curve because it's not effiecient. You should choose another pump if that is the case.

Believe me yet?

[Doahh]

If your going to reduce the flow I still say T it off and run it through your equipment...
Or like this

|
|_V_
|.....|
P

V is valve
P is the pump

That way there is no back pressure on the pump other than the normal operating head

[Kewlworm]

Coo! I am going to have a nice read at starbucks!

[Kernel Panic]

Getting back to thte orginal issue, the splashing is from the distance the water is falling and the rate of water movement. You simply need to decrease one or both of these factors.

By increasing the water level height in the retun pump chamber or...

A 1262 is likely overkill for your system, if return flow is not the only flow in your system. I assume you have a skimmer? You don't need to turn over your system much more than your skimmer's turn over. (If your skimmer flows at 360gph, then have your retrun pump at nearly the same.) You could consider an Oceanrunner 2500 for a return. A lot of people seem to like them.

[Pbrown3701]

Originally posted by Doahh
If your going to reduce the flow I still say T it off and run it through your equipment...
Or like this

|
|_V_
|.....|
P

V is valve
P is the pump

That way there is no back pressure on the pump other than the normal operating head

Technically, it would be best to operate the pump at it's BEP (Best Efficiency Point). This will prolong the life of the pump and use the least amount of electricity for the amount of work being done (water being pumped).

Thus, if you're operating to the right of the BEP on the graph, then you would be better off restricting the output to increase the head pressure.

If you're operating to the left of the BEP, then you would be better doing as Doahh above suggested and creating an alternate or parallel route (thus decreasing the head on the pump).