Waterfaaaalllllllll !!!!!!!!

[cichlidChad]

I know there are a lot of posts along these lines, but I am kind of lost.

I need a new pump for my waterfall in my ~500 gal pond. The hose is about 11ft long and the falls start about 3ft above the surface. Last summer I had a pondmaster mag 18 which gives 1800 gph, and I got a slow trickle out of it. Is this pump just underpowered, or do I need to check my hose for debris or kinks? I am not sure.

Here are a couple that I am looking at...

Central Machinery 4800 GPH Waterfall Pump @ Harbor Freight for 129$

Central Machinery 4000 GPH Waterfall Pump @ Harbor Freight for 99$

Sorry, no links since this is my first post. :icon_mrgreen: The price seems good. Can anyone vouch for the quality of these? Thanks in advance. :100:


-Chad

 

[Norm]

Two specifications are required to correctly size a pump. You have them both. The 1st is flow rate which is usually given at 0 ft. of head. (Well head for those with dirty minds). Head is the height that the pump must lift the water. So for a well that is 100 ft deep the pump must lift the water from the bottom to the top or 100 ft of well head. For ponds the head is usually much less and for you its sounds like you have 3 ft of head.

Pumps should have a plot of flow vs head. The max flow is at zero head and decreases as the head increases.

So you need to find a pump that has your flow rate at your head.

Hope that helps

 

[koiguy1969]

they say that 10' of horizontal run is equal to 1' of vertical, so you have 4' of head heigth. a waterfall should have 100 gallons of flow per inch minimum. how wide are your falls? maybe take the pumps impeller mechanism apart, clean and reassemble. i dont know your pump ratings but thats just a general guide line.

 

[cichlidChad]

the falls is about a foot wide. i am using a plastic reservoir that i purchased online. the pump was new when i first tried it, and the flow just wasn't there. i saw this when i tested it before i buried the hose as well.

by the way, i am using a thick plastic plumming hose from menards. so it is possible that this could get pinched at some point, even though i am only burying it 5 inches or so. would it be better to go with pvc?

i checked the performance charts for the mag 18, and i should be getting 1375gph with 4ft of head.

ideas or suggestions? are the pumps above decent? overkill?


-chad

 

[koiguy1969]

that flow rate is o.k but you dont seem to be hitting it, does the pump have a flow rate dial, its on the inlet side if it does, the tetraponds do, i dont know about the pondmasters. if so maybe you just need to open it more. i cant see running a 4000+ pump in a 500 gallon pond, not to mention the water wont spend much time in the filter, so the bacteria wont have much time to do its thing. you could run the pump your using and add another pump directly to the waterfall when you want to enjoy the sights and sounds of a stronger flow, just turn it on. i am considerig that myself, i would hook it up to one of those remote control plug setups.

 

[cichlidChad]

by the way, here are some before and after pics. i am starting to think my falls might be a bit too wide for my pump to handle. let me know what you think.

before

during construction

after

 

[cichlidChad]

-chad

 

[David]

Almost all waterfall calculators online forget or do not know how to include the resistance created by fittings, number of 90° bends, reducers, and the tubing length.

You also must account for the effect of gravity on the water that you are lifting (head height).

So let’s consider the look that you are looking for.

For every inch of waterfall width you will need:
GPH = Water thickness
125 = 5/8"
140 = 3/4"
186 = 1"
252 = 1-1/4"
324 = 1-1/2"
405 = 1-3/4"

But this flow rate is at the top of the falls and you still need to know the resistance of your pipe and fitting.

So I typed in some numbers for you.

But please remember that you do not want to pay for a pump that is over powered year after year.

That you want is a look for your falls.

12 = Inch Spillway Width

140 = Number Of GPH That You Want to Pass Over The Falls = 3/4 inch of water at the waterfall spillway

3 = Foot Vertical Height

2 = Number Of 90° Bends, Reducers

11 = Feet Of Tubing Length

4 = Number Of Adapters Or Fittings

Then I pushed calculate and it produced this.

You will need a pump that produces 1680 Total GPH at a head height of 6 feet.

Note that the extra height accounts for the resistance.

I create my own online calculators.

I use java script to do this.

At this time I have 10 calculators online and can calculate round or square ponds.

But I am the only one that includes the dynamic head pressure into a waterfall calculator (that I know of)

 

[cichlidChad]

Wow, thanks for the info David. So, according to your calculations, my current 1800 gph pump is sufficient. I guess my main option is to take things apart this spring and play around with it.


-Chad

 

[koiguy1969]

most submersible pumps have a greater pull than push so its a good thing to locate your pump close to your falls and use a prefilter attached to a hose ran to the area of pond where youd like to draw the water from, just allows less resistance in water flow. that is if your pump has the ability to use a prefilter plumbed on. and if you want to change draw areas you just move the prefilter, or tee off the hose and draw from two areas to avoid dead spots. thats what i do.

 

[Norm]

I like this idea of a movable "drain."

 

[DrDave]

That is the neat thing about submersible pumps. You can move them around untill you find the optimum position.

 

[DrCase]

CICHLIDCHAD It is best to use a hard pipe ,or suction hose that will not kink up

 

[D&RW]

Very nice looking pond. Is this your first? Nice job.

Sure seems like you should be getting a bit more than a trickle, but sometimes pumps don't perform even at their stated capacity. There are simple methods of measuring pump output listed on some of the pond websites.

One thing you could do is add a second pump and run it straight into your waterfall, i.e. bypass the filter so the filtered water still goes through at the desired rate. If you speed it up too much you can lose filtration effects.

 

[27goldfish]

gotta question. I just bought a tetra pf1 for filtration. Will the output be enough to do a waterfall with a nice flow if I do a spillway with a 2000 gph pump with a max lift of 23ft? Or will the output just kinda come out really slow. I have never had a pf1 and am curious.

Here is the pump:
http://sunterrausa.com/pumps/product/202000