Submersible Pump - Push/Pull? Larger Tubing?

[Wildneg]

So I have my intake bay kind of done. At least the seam is done and attached, where the pond water is now rushed in and made it full.

I have 2 submersible pumps. One is a 5200 GPH and the other is about 2500 GPH.

The 5200 pump was originally, sitting on the bottom (on a small crate, probably 6" above bottom) pulling water directly into the inlet. It has one of the 'screens' on the inlet side to prevent anything from getting sucked in. That pump runs up about 4' and then splits off to x2 1" lines. One of the 1" lines goes to the waterfall. The other 1" line splits off again into x2 1" lines. Each one of those lines has a valve to turn it on/off. One of those 1" lines goes to the waterfall as well and the second 1" line goes to the bog filter.

So basically, this main pump always has the 1" line going to the waterfall. If I ever need to, I can divert that second 1" line off this 5200 GPH pump to the waterfall as wall (more water down the waterfall) or to the bog if my dedicated bog filter pump goes out or just need to move more water through the bog filter.

The 2500 GPH pump pulled in water from one of those oase skimmers which adjusted with the water level. It is small and was just a quick fix until I had time to do something with an intake bay. So it is 1.5" pond tubing from the inlet side across the pond to the oase skimmer. Basically flat run, 4' under water on the bottom. The run is a full 20' of tubing.

So with the intake bay operational other then needing to tuck in the liner/landscaping/etc...
I removed the screen on the 5200 GPH pump and attached a 1.5" pond tube. I have about 40' of 1.5" pond tubing running from the pump inlet, laying on the bottom of the pond going over to the intake bay. The tubing raises about 2' to my upper cliff where it runs the rest of the way to the intake. So if anything, the pump isn't pulling UP but actually pulling DOWN if that makes any sense.

When I did this, my water flow was reduced significantly in the waterfall. I understand the longer run will cause some resistance and lower the throughput of the pump. What is strange, at 20' of hose on the inlet side, I noticed no changed at the waterfall. When I added the second 1.5" pond tubing at the end of the first tube to get me into the intake bay, that is when I noticed more then half of my water throughput gone. I'm going to check the tube and the propeller and make sure I didn't suck something up but I didn't think I did.

I'm still in trail mode here before I finish it all off. But with almost no head lift here (or actually none really since the open end of the tube is HIGHER then the pump), I'm not sure why it would be reduced by so much. The tube is all in the water as well, sunk to the bottom of the pond as it should.

My goal is to pull water for the smaller pump as well, from the intake bay. This way my pond circulates from 'left to right', causing everything to go into the intake bay (leaves, debris, baby fish, my children that fall in, etc). I'm just concerned now my 5200+2500 GPM I was getting (not the full amount but ALOT more then I am now with the 5200 pump), will be reduced significantly going this route.

So I guess my questions are...

• What if I extend my power to the intake bay and put the pumps directly into the intake bay, into a pump vault?
  • My thought is, its still 40' run to get back to the original lines running to the waterfall and bog filter. Would the pump be more efficent pushing the water 40' then trying to suck it in 40' like a straw.. although a pretty much horizontal straw...
• What if I try using 2" pond tubing, giving it extra 'volume' that can sit in the tubing that will be replenished naturally since the tube is under water?
  • Discussing with my dad, he didn't think that would make any difference. I thought it would supply extra volume of water available closer to the pump inlet. Maybe I'm dreaming here.

Maybe I'm just over thinking all this. If this is the price to pay to have the bog filter/waterfall at one end of the pond and the intake at the other, then so be it. I may just have to get larger pumps that I know will only produce 50% of the waterflow. So my 5200 GPH may need to be a 10,000 GPH pump, knowing I'll at least get my ~5000GPH back.

I'll be checking the pump's housing/propeller to see if any debris is in there. I know my smaller pump, when it was hooked up to the oase skimmer would get very clogged with debris. The flow would reduce by probably 75%. I would notice it right away and clean it. Happened a few times. So maybe that is the issue. I'll report back once I check the pump out though.

Any thoughts or feedback would be appreciated. Trying to get this rocking so I can have all those damn leaves accumulate in one area of the pond and not need cleaning 5x a day. Maybe I can train the children to skim the pond for me... haha.

Any questions or need more diagrams, let me know! Hope the diagrams help in my explaining!

 

[fishlips]

Wow thank you for all the info. I must admit it was a bit to digest however my first thought is ( deep breath) to put 5600 gph in a 1" line split into 2 needs 3 psi over atmosphere to get 51.67 us gal/min not normal in a circulation pump.

The rule of thumb here is go one size larger then the pump max output fitting size. So if the pump has a 1 1/5 fitting we go to 2" to reduce dinamic head pressures. This needs to be accounted for at ever junction.

I will redigest this again with a fresh mind.

 

[Wildneg]

The pump was pushing a lot of water out. I'm not sure of exact as I was never able to measure it like I did with my second pump.

When I ended up extending the inlet side of the pump into the intake bay, that is when the water flow dropped by probably 50%. I have seen a lot of designs/videos where they put these pumps in and basically move water from the right back to the left with very long runs, to create that 'left to right' movement/circulation.

I may not have the right pump (strong enough?) OR maybe by design, these pumps are better at pushing the long distance then pulling. Even though the tubing runs a long distance horizontally (only about 4 or 5' lift total), I would have expected it to pull a similar amount of water as it did before. I expected some loss but not 50%. So maybe if I get time during my lunch break with work, I can try moving that pump over to the intake bay. I'll attach the original 'inlet' hose I was using to the outlet of the pump and just let the pump pull the water directly from the intake, PUSHING the water the 40'. Maybe it will be more efficient.

Though to your point, that 1.5" split to x2 1.0" lines... maybe what I'm doing here is bringing that issue to light as well. I can change that out next spring if it'll help even more. I want to at least try getting this pump working back at the rate it did before. I know I don't have that 'measured' amount but I can just notice the water coming down that water fall is like half when I added that tubing for the inlet side of the pump.

Any tips/help/thoughts would be greatly appreciated. I will give some feedback once I move that pump out to the intake bay and run the temp power out there.

Thanks!

 

[fishlips]

Pushing or pulling I don't think you will get passed the TDH. The pumps volume and pipe size broke this web page.

 

[Wildneg]

Pushing or pulling I don't think you will get passed the TDH. The pumps volume and pipe size broke this web page.View attachment 154637

So what are the options? Would I need to increase the pipe size? Sounds like I would need to do that regardless of which pump I get.

I may run out there and look at some options later today and JUST TRY to move the actual pump into the intake bay. And I just looked outside and wouldn't you know it? It is freaking snowing! It will not stick or anything like that, just absolutely shocked as it is just October. Northwest Indiana!

 

[fishlips]

Snow huh, Well if you stuck inside time for a little research.

WATER FEATURE DESIGN SERIES 6 | PUMP TYPES-PUMP CURVES-AND TOTAL DYNAMIC HEAD

 

[Wildneg]

Took a look at that calculator. I noticed you had 5200 for GPM. I think that should be about 86 GPM. If I plug that in, I'm at about 7.2 ft of 'head height'. With the pump curve, that is roughly 2700 GPH/43 GPM. It cuts the throughput about half. Plus the run on the OUTPUT side. I'm guessing about 2000 GPH maybe? I'll check my cad drawing and measure the length on the output side.

I'll finish watching that video though. He did mention at the start, changing hose size could help. So I need to finish watching to see if that will apply with my issue.

I think the waterfall is still not pushing anywhere near 2000GPH but I can't really determine without unhooking and filling up a bucket directly. But I feel a little better that... it could just be the limitation of the pump. May just have to get a second pump. I did trench/run an extra electric line thank god.

 

[netvine]

The pond tubing has a lot more head than schedule 40 pvc. Ideally you would use regulsr pvc over the flexible pond tubing. Also, It seems like your idea of putting directly in intake bay vs long pull will have a dramatic effect on your pressure vs a long run of pond tubing intake. Generally you just want to push and not pull at all. Dont want to restrict input that much.

#1 FlexPVC®.com Water Flow Charts Based on Pipe Size (GPM/GPH) ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

Water Flow Volume for a given pipe size based on charts, tables, formula, nomograph, & experience.

flexpvc.com

If you can afford it use at 2-3” schedule 40 pvc from 5200 to waterfall. The 1” tubing is restricting a lot of flow and very prone to failure.

 

[Wildneg]

@netvine - So the 2" PVC Sched 40 would be a bit. I can do that next spring for sure and lay the pipe on the pond bottom (keeping everything in the water). I'm not sure if it is warm enough for me to get it all done this fall. I was just out there checking some things and it is COLD. Water is about 42 degrees currently too. I would probably have to get in to lay that pipe exactly as needed since it isn't flexible and 'forgiving' with how I lay it.

The TDH calculator does in fact go from about 30/ft TDH to 7/ft TDH when I update 1.5" to 2.0" rubber hose. So that will make a huge improvement it seems. I may try finding some affordable 2" rubber tubing online if I can. I think my pump comes with a 2" barb as well, so should match up. I may try running that to the inlet side and see if it improves. Based on what the calculator shows, it SHOULD. I would leave the run to the waterfall the same as it is for the rest of the fall/winter. I can upgrade that in the spring too. This may get me the water movement I need to draw those leaves into the intake bay. If not, the only other thing I can do before next spring is try moving the pump INTO the intake bay and then PUSH the water through the 40' of 2" tubing (once I upgrade the tubing to 2" for the fall/winter). Like you mentioned, it will push more efficiently then trying to pull.

I'll order extra tubing if I can find some cheap enough, to do the same with the 2700 GPH pump as well. That way ALL the water is drawing in from the intake bay. That should help pull all the debris into here.

I'll post some updates once I can get this done. Appreciate all the information though from everyone! Has helped me understand the math much better.

 

[fishlips]

I did put in the wrong number how embarrassing.

Welcome to the forum

Can you upload some pictures we all like see.

 

[Wildneg]

I did put in the wrong number how embarrassing.

Welcome to the forum

Can you upload some pictures we all like see.

I will get some pics. It is an 'irrigation' pond first (to irrigate my lawn) and a fish pond second. The landscaping still has to be done but ran out of time. Lots of plants to get planted in the spring and I have a lot of stone sitting around that will be used in the spring. Work is cut out for me!

I'll try getting some up here today if I can.

Don't feel bad about the number in wrong. When I wrote the original post, I had to go back and change the GPM to GPH because I kept messing it up. Trying to keep it all straight. I only caught the 5200 instead of 86 because when I watched the video you recommended, the tool he used was in GPM. I thought "Wait, I think I was putting in GPH too!".