Pump advice

[Jackie Ramo]

OK so I am looking for 2 new pumps. One submersed and one not.

Terri says the new filter can not do more than 2200 gph.

For this I am looking at a MDM Sequence 750 Series External High Volume Pump 3600GPH ----- 2800 GPH @ 4 feet of lift, 2500 GPH @ 6 feet, 1900 GPH @ 8 feet of lift, 1400 GPH @ 10'

I figure the lift is about 7 feet, not sure if lift and head are the same thing

OR

MDM Sequence 750 Series External High Volume Pump - 4200GPH ---3400 GPH @ 4 feet of lift, 2550 GPH @ 6 feet, 2305 GPH @ 8 feet of lift, 1650 GPH @ 10'

Supposedly backing down a pump is good for it... seems contrary to me but its what they say.

[Koidaddy]

Jackie, I believe lift or head is measured from surface of water upwards.... Are you sure you need 7' of lift?
:4eyes:

[philly]

From what I remember lift is the height and head is the pressure pushing through elbows, bends and restrictions, correct me if I'm wrong and lord knows sometimes I am, the MRS will agree with that. :HAHA:

[Jackie Ramo]

Phil, you are the plumbing guy you should know this stuff.

The filter will sit behind the waterfall but lower but there will be about 15-20 ft of pipe and I am sure elbows etc plus ball valves, gate valves and chacha valves.. I think the lift will only be about 2-3 ft

The problem is they don't seem to make external pumps for small filters like this one. There is a smaller version but it is $200.00 more, not less than these.

[philly]

Jackie, I see no need to buy a lower rating pump for more money, just buy the largest pump for the best price and we will install a tee before the filter and divert the excess water somewhere else like the waterfall so which ever way you go the correct amount of flow will go to the filter, easy as 123. :yesyes:

[Jackie Ramo]

Diverting through the waterfall will be far from easy. So the smaller one and we will cut it back.

[philly]

Well you don't have to run the piping to the waterfall, you can let the water flow about 3" to 5" below the top and across the pond that would give the koi some exercises. :smile:

[Jackie Ramo]

That is what will happen but I don't need two. Also I don't want more pipes in the garden. Makes it hard to weed.

[philly]

My dear pipes can be buried you know. :yup:

[Koidaddy]

Taken from: http://www.koifishponds.com/new_page_1.htm

"Pump Head
The proper pump is the heartbeat of an effective pond system!



Before you can pick the best pump for your pond, you need to determine what flow rate and total dynamic head (TDH) you need. Since the flow rate is reduced by the head it is working against, you must know both of these parameters as well as others to properly select a pump
Flow
The exact flow you will need depends on many factors including the size of your pond and waterfall, as well as the amount of fish, plants and sunlight. In general, most ponds will operate nicely if you turn the water over approximately once an hour. This means if you have a 4000 gallon pond, you want about 4000 gallons per hour, or 67 gallons per minute.
Head
Head is a measure of resistance to flow. If a pump has a maximum output of 20 head feet, it means it can pump water 20' straight in the air. If a pump is rated at 50 gallons per minute at 10 feet it means it can overcome 10 feet of head (TDH) and still deliver 50 GPM. As you increase the head, you decrease the flow rate, and increase your operating costs. To maximize your flow, you must minimize your head, which also minimizes your operating costs. For pond applications the 3 main sources of head are:
Static Head - This is the vertical distance you raise the water. To determine your static head, measure from the surface of the pond (vertically), to the highest point in the discharge line where the water is discharged to the atmosphere. This is usually the top of your biological filter, fountain, or waterfall.
Friction Head - As water flows through pipe and fittings there is resistance. The higher the flow and/or the smaller the pipe, the higher the resistance. Determine your overall pipe length, including adding in the equivalent length for your fittings. Consult the friction loss chart. Find where the column for your pipe diameter intersects the row for your flow rate and read the friction loss per 100' pipe. Use large enough pipe to minimize friction loss. It is usually best to keep your friction loss (per 100 feet of pipe) to less than 6 feet. In other words, once you know the desired flow rate, pick a pipe diameter, or schedule, that will give you less than 6 feet of friction loss per 100 feet of pipe.
Friction Loss - THIS CHART GIVES FRICTION LOSSES FOR YOUR GIVEN FLOW RATE PER 100 FEET OF PIPE: EXAMPLE; IF YOU WANT 60 GALLONS PER MINUTE, AND YOU'RE USING 2 INCH SCHEDULE 80 PIPE, AND YOU HAVE A 160 FEET OF PIPE, YOUR FRICTION LOSS IS 8.12 x 1.6 = 12.99 FEET OF HEAD. So we would either want to use schedule 40 pipe, or go to 3" schedule 80 pipe.
Fittings Loss - Now go to the bottom of the Friction Loss page and pick out the number and type of fittings you are using (use the worst case scenario if you have a bypass): Example; a 2" 90° elbow is the equivalent of an extra 6 feet of 2" pipe, so if you have ten 2" 90° elbows you would add 60 feet to your pipe length. After adding the extra feet for all your fittings you recalculate your total feet of head. In this case it would add 60 feet to 160 feet for a total of 220 feet or 2.2 x 8.12 = 17.9 feet of head.
Pressure Head - Any additional pressure required by sand filters, spray nozzles, etc. must be calculated. The conversion is 1 PSI = 2.31 head feet.
If our sand filter runs at 10 PSI, that would add 23.1 feet of head to the 17.9 feet required to overcome the friction loss of our pipe and fittings. So now the total pump head is 41 feet without considering the static head. (Notice that the pump head will increase as the sand filter gets dirty and increases the back pressure.)
Total dynamic head ( TDH) - Add your static head, friction loss head, fittings loss head, and pressure head.

Type of head
Source
Calculation
PH

Static Head Waterfall 10' - above surface of water 10.0

Pipe Loss 2" Pipe 8.12' per 100 feet of pipe 13.0

Fittings Loss 6' per elbow 10 2" 90° elbows = 60 ft 4.9

Pressure Head Sand Filter running at 10 psi x 2.31 23.1

Total Pump head in feet
51.0

Don't forget to add up the equivalent feet of pipe for all the fittings.
Now that you know your flow and head, you can select a pump that provides this performance, and does so efficiently.
Performance Curves
Now we know that we need a pump that can handle 67 gallons per minute at 51 feet of head. This information can be found on the performance curves for the pumps.

Maximum Efficiency Area
We want to select a pump that has these results inside of the maximum efficiency curve area.

Lowest Operating Cost
If we have more than one pump that meets all these requirements we can then select the pump with the lowest operating cost, i.e., lowest amps or watts.

Remember, a 230 volt motor will run at half the amperage of a 115 volt motor, but wattage is the amps times the voltage, so we have not gained any cost savings because we doubled the voltage.
A 2 horsepower motor can cost $2,000 per year to operate.
Lowest Noise
We also want a pump that is quiet enough to allow us to enjoy our pond. Most manufacturers can supply a noise number in decibels (dB) at 3 feet from the pump. We want the lowest dB possible. We can also mount the motor on rubber noise isolation pads, or shield it with noise attenuating "walls". "

[philly]

KD since you're such a techie how about resistance in the filter when it starts filtering and when the bacteria starts to grow inside the pipes which causes resistance. :frisbee:

[Jackie Ramo]

lalala lalala lalala I just want it to work and I don't want to know how it works or why it works and it better be damn quiet while it does it. All that plumbing pump stuff just makes my head go crazy. Not that it isn't crazy already. Idon't want toknow how the car runs or why the oven works or how electricity gets to my house. I just want it to work. Luddite, don't forget.

[philly]

OK OK calm down I don't want to be the one to give you a nervous breakdown as I know you are already somewhat crazy, get the pump you think is the best for the job and I will help you install it. :grin:

[Jackie Ramo]

Spoke to Terri on the phone and decided on a pump and between her and Phil I will be dragged kicking and screaming into the modern world.

Phil it is the 4200, so we will need two returns to the pond.... how do I get talked into these things. :jaw:

[philly]

Well considering you got Terri and myself to help out you're doing fantastic in this modern world even if you did not know a thing about ponding, but you probably know much much more than I will ever know.
:lol:

[Jackie Ramo]

I know nothing about nothing. :yup:

[philly]

You sound like Schultz's from Hogans Hero's. :HAHA: