Pond pump and piping advice

[miamicuse]

I have a pond with a volume of 1600 gallons, depth varies from 16"-28" average depth 24".

I have recently drained the pond to do a complete cleanout and am in the process of repairing plumbing - tree trimmer dropped a 16" diameter tree branch down 30' from above and hit the PVC pipe in the pond and broke it.

The current pump is a pool pump - I think the last owner of the property/pond upgraded the pool pump from a single speed to a variable speed and decided to move the single speed to the pond. I think there may be a better more energy efficient less noisy pump. So as I am trying to redo the plumbing I am trying to improve at the same time.

(1) On the suction side the piping is 1.5" PVC pipe that is terminated with a home made foot valve strainer. It is a piece of 24" long 4" PVC pipe with holes drilled every inch or so. This contraption is then connected to the 1.5" piping that travels about 25' to the above ground pump. Here are some pictures of this contraption.

My question regarding this contraption...

(A) should I continue to use it or is there something better available?
(B) This contraption was at the bottom of the pond, and therefore due to debris over the year it basically was half buried in muck when I cleaned out the pond. Should I place it higher? If so how high? 6" from bottom? 8" from bottom? 12" which will be half way?

(2) Should I replace my pond? The current above ground pump is a pool pump Pentair Sta-Rite Dyna-Glas/Dyna-Max series with a 1HP motor. The suction side piping runs about 25' to the pump, and the return side is also about 25' but then it goes up vertically to a water feature. Pond is 1600 gallons, 120V electric at the pump. Should I consider changing the pump and if so, any recommendations?

Thank you!

 

[tmvandervort]

I have 2 ponds connected by a spillway probably less than 3000gallons. My experience with a pool pump was, it eats way to much wattage( around 750) and it tubulates the water so much it didnt allow for any biological filtration. I use 2 laguna 2400 pumps at 84 watts each. One operates filter system,the other runs the waterfall. Hope this helps. Also the pump prefilter(no media) is mounted on a milk crate. If you ever have a pipe blow it won’t empty the pond

 

[DerekOR]

Definitely you should get an external pump made for ponds. Poster advice suggested Laguna. Sequence pumps are also good, I have 5800 version, and they take 300w. If you go with one of these they will likely pay for themselves in electricity savings.

On that makeshift strainer, I would think that would really starve the suction. It doesn't look like enough surface area. It is not good to starve the suction on a centrifugal pump. I would find a way to get more open area. Longer pipe, more holes, something.

 

[miamicuse]

Definitely you should get an external pump made for ponds. Poster advice suggested Laguna. Sequence pumps are also good, I have 5800 version, and they take 300w. If you go with one of these they will likely pay for themselves in electricity savings.

On that makeshift strainer, I would think that would really starve the suction. It doesn't look like enough surface area. It is not good to starve the suction on a centrifugal pump. I would find a way to get more open area. Longer pipe, more holes, something.

Thanks.

I wonder if there is a way to somehow calculate if I need more holes or bigger holes on that strainer body. My day job is in structural engineering and I vaguely remember some fluid mechanics courses I took years ago. There has to be a way to compute how many holes and each hole's size for the pump's optimum flow rate.

 

[DerekOR]

Thanks.

I wonder if there is a way to somehow calculate if I need more holes or bigger holes on that strainer body. My day job is in structural engineering and I vaguely remember some fluid mechanics courses I took years ago. There has to be a way to compute how many holes and each hole's size for the pump's optimum flow rate.

I guess you could calculate the area of a 1.5 inch pipe. Then calculate are area of one small hole, and then multiply by the number of holes to compare. My guess is it is 20% or less. So, my guess is you are really choking the flow.

 

[miamicuse]

I guess you could calculate the area of a 1.5 inch pipe. Then calculate are area of one small hole, and then multiply by the number of holes to compare. My guess is it is 20% or less. So, my guess is you are really choking the flow.

let's try that.

area of 1.5" diameter pipe (nominal) = 3.1415926X1.5X1.5 = 7.07 in^2
area of each 3/16" hole = 3.1415926X0.1875X0.1875 = 0.11 in^2

7.07/0.11 = 64 holes

I have about 110 holes so may be OK?

 

[madsande]

I have a pond with a volume of 1600 gallons, depth varies from 16"-28" average depth 24".

I have recently drained the pond to do a complete cleanout and am in the process of repairing plumbing - tree trimmer dropped a 16" diameter tree branch down 30' from above and hit the PVC pipe in the pond and broke it.

The current pump is a pool pump - I think the last owner of the property/pond upgraded the pool pump from a single speed to a variable speed and decided to move the single speed to the pond. I think there may be a better more energy efficient less noisy pump. So as I am trying to redo the plumbing I am trying to improve at the same time.

(1) On the suction side the piping is 1.5" PVC pipe that is terminated with a home made foot valve strainer. It is a piece of 24" long 4" PVC pipe with holes drilled every inch or so. This contraption is then connected to the 1.5" piping that travels about 25' to the above ground pump. Here are some pictures of this contraption.

My question regarding this contraption...

(A) should I continue to use it or is there something better available?
(B) This contraption was at the bottom of the pond, and therefore due to debris over the year it basically was half buried in muck when I cleaned out the pond. Should I place it higher? If so how high? 6" from bottom? 8" from bottom? 12" which will be half way?

(2) Should I replace my pond? The current above ground pump is a pool pump Pentair Sta-Rite Dyna-Glas/Dyna-Max series with a 1HP motor. The suction side piping runs about 25' to the pump, and the return side is also about 25' but then it goes up vertically to a water feature. Pond is 1600 gallons, 120V electric at the pump. Should I consider changing the pump and if so, any recommendations?

Thank you!

Sequence pumps are work horses. If you can manage the larger upfront cost you will save money in the long run.

 

[DerekOR]

I have had 4ea for 2+ years, and they are fantastic. I will be a customer for life with Sequence.

 

[GBBUDD]

Your 4" contraption as you call it is not something i see as beneficial. my Understanding is that was attached to the outfeed from the pump? If that is the case you want the pump to push as much water as possible so if the return is in a 4" pipe with relatively low flow due to the size of the pipe and pumps. then the water is being disbursed too much you want the return to push water around the pond keeping with good circulation. to stir up areas keeping dead spots to a minimum

 

[miamicuse]

Your 4" contraption as you call it is not something i see as beneficial. my Understanding is that was attached to the outfeed from the pump? If that is the case you want the pump to push as much water as possible so if the return is in a 4" pipe with relatively low flow due to the size of the pipe and pumps. then the water is being disbursed too much you want the return to push water around the pond keeping with good circulation. to stir up areas keeping dead spots to a minimum

Sorry I didn't see this till now.

The 4" contraption is not on the return side. It is on the suction side. The majority of the pipe on the suction side is 1.5", but at the end, I enlarged it to 4" with holes so it can suck in water but minimize debris. The return side of the pump runs up to the top of a boulder and exits there to run down the boulder back into the pond.