How to calculate what pump to use

[Nepen]

Hi all,

I’ve been planning my new pond for the house we just bought. The house actually has a concrete pond at the front but I rather have my pond in the back and with good filtration. The concrete pond needs a lot of work too.

Anyway, I’m planning to have about 2600 gallon pond and about 1000 gallon bog, connect together with about 20 feet long 3 feet wide stream. I’m hoping to have 2 pumps. Thinking one will be in a skimmer and one will just be in the pond. If there is no tree around, should I need a skimmer? Any suggestion on which is good?

So the piping will be at least 20 feet long, the pond will be about 3 feet deep, the pump from the skimmer probably has about 9 feet of head pressure (with the fitting and everything calculated) and the one in the pond has about 13 feet head pressure I think.

With the 3 feet wide stream, what is the good gph I need to get that will produce a good enough flow?

I’m thinking one 4200 and one 2900. Will that be over kill for my 2600 gallon pond? Will that be enough for my stream?

Can I use laguna max flo in the skimmer?

Thanks,

Anya

 

[sissy]

I have no skimmer and no need for one either .It also depends on size of pipe .like my 2900 gph uses 1 1/2 inch sump pump hose and the 2400 gph uses 1 1/4 inch sump pump hose .1 has 12 ft of hose to filter and to waterfall and that is the 2900 gph and 2400 gph has 8 ft of hose to the other filter and rest just goes in the pond under the bridge

 

[dieselplower]

Nepen just to be sure you are aware, "head" should be calculated from the surface of the water, not the depth at which the pump is placed. I imagine the pump in the skimmer will actually be farther away from the beginning of the stream than the pump in the bottom of the pond, if you measure from the water level?

 

[JBtheExplorer]

I don't have an answer, just want to say I'm looking forward to seeing the process of that pond when it happens!

 

[RobAmy]

My gallons is about the same as yours once you combined yours. I use a 4700 gph in the skimmer and 2 1800 gph in the pond. I have the 4700 and 1800 going to the stream and the 1800 come out in a different area of the pond. My stream is 19ft but a bit wider at 6ft. I personally love the flow. The sound is very pleasing. When I do maintenance and shut down the 4700 in the skimmer the 1800 is running on its own and it is a very slow flow rate. I think you're spot on personally with the pumps you picked out. As far as the skimmer that is very personal but when I redo or upgrade mine I will actually have to skimmers not just one. They make pump maintenance so much easier then when they are in the pond. Even that you will have no tree there is always wind, floating algae etc that is could be useful for. I also think is adds a nice push pull effect in the pond. I am not sure about the laguna in the skimmer, will most likely depend on the size of the skimmer you pick out. I have the Savio which I do not think it would fit but something like the helix which is much bigger would probably fit fine.

 

[sissy]

But still length of hose does calculate into it and there are video's on you tube that show the difference and laguna explains it also on there pump sight .My head on 1 pump is 3 ft the smaller pump is 2 ft.Laguna sells skimmer pumps also .You can also take the max flo out of the cage

 

[dieselplower]

Sissy I know you like to comment on every single thing but the fact is, either Nepen has calculated the head incorrectly, or the pond is designed improperly. The skimmer should be on the opposite side of the pond as the incoming water from the stream so it should be the furthest away, and therefor, have the most head.

 

[RobAmy]

You can also take the max flo out of the cage

Very true, that may fit in the Savio now.

 

[sissy]

Sissy I know you like to comment on every single thing but the fact is, either Nepen has calculated the head incorrectly, or the pond is designed improperly. The skimmer should be on the opposite side of the pond as the incoming water from the stream so it should be the furthest away, and therefor, have the most head.

I guess than I should not help anyone since I just went through the pump hunt .all I have to say .

 

[Nepen]

Thank you all Sissy, I do like to here your input

Diesel, I calculated my pump head from several things..I add 1 foot to every foot in height, 2 for every 90 degree corner fitting, 1 for every 10 feet of hose/pipe, and 1 for other type of fitting.

So the pump in the skimmer is going to be only about 2 feet below the ground I think? I might calculate a bit off but it should be less head then the one in the pond if I put the pump at the bottom of the pond, but I don't think I will (just thought of it now) so they should have probably about the same head pressure, now that I think of it more. The skimmer will be furthest away but the shape of the pond make it closer to the out put in the bog.

But since you say it start calculating from the surface of the water.....hm... That makes it a bit different. A little Less than my original calculation then since the bog will be only a foot higher than the pond. Thanks

Rob, I actually looked at your pond showcase and base my idea for pump from there too 6 feet stream looks so pretty but too big for me how deep is your stream? That's one thing I don't really understand how to calculate the volumn of water going through stream. I didn't know I need to calculate the bog together with the pond volumn for the pump size?

JB, it might be a while yet, I need to clear the wisteria around the house first, right now we don't have any land we can use since the dang thing take over everything. My husband is getting me 20x50 roofing liner that I can use so I'm building my design base on that

I might try to make my own skimmer box, any suggestion of how best to do that?

 

[morewater]

If you're going to build a pond, don't cheap out on the liner. Nix the roofing membrane and get a proper EPDM liner. It's the most important purchase that you'll make. A proper 45mil EPDM in that dimension is going to run you about $400-$500, but it'll last. Prepare for some heavy lifting with that size of liner.

 

[Nepen]

Hi morwater. The roofing liner is EPDM 45 mil my husband can get it cheaper just coz he also has a roofing company. Thank you for your concern though

 

[Nepen]

I just bought the pump off ebay. both laguna. One is 4200 for $179 and other 2900 for $155. The 2900 gph is the 'new' version. I'm excited.

 

[herzausstahl]

Nepen just to be sure you are aware, "head" should be calculated from the surface of the water, not the depth at which the pump is placed. I imagine the pump in the skimmer will actually be farther away from the beginning of the stream than the pump in the bottom of the pond, if you measure from the water level?

Dieselpower, can I ask why you negate the depth of the pump in the water from your calculations?

 

[Dave 54]

Nepen we have an Oase 3500 on our pond and its only 1,000 gallons Imperial

Dave