Koi pond! Really confused.

[GBBUDD]

How are you unsure? you cant push through a 1 1/2" pipe the same amount of water that a 6 inch or for a closer reference even a two inch line can push. your max will only be what ever the smaller pipe is. sure you cant jack the pressure but equal pressure to both and 2 inch wins everytime

 

[combatwombat]

That's correct, but we're not talking about equivalent lengths of pipe. The factor is only the size of the outlet of the skimmer, which is a small part of the whole pipe system.

The way I read your post is that whatever size outlet you have on your skimmer, pump, whatever—that's the size pipe you should use because anything else would be pointless.

Many (maybe even most) pumps I've seen up to about 7,500 gph have a 1.5" outlet. If I wanted to deliver 6,000 of those gph to somewhere 100' away, should I use 1.5" pipe or upsize to 2"? Or even 3"? I've never seen pond pump or skimmer with a 3" outlet, but 3" pipe is used all the time because it reduces head loss over long distances.

Apologies if I misunderstood what you were saying.

 

[JesseMoreira06]

What’s your soil like? Standard wisdom is to use a non-woven fabric in the 5-8oz range.

Very clay like, so maybe that is why for the cheap prices, from what I see its all woven at my local hardware store.

 

[GBBUDD]

The way I read your post is that whatever size outlet you have on your skimmer, pump, whatever—that's the size pipe you should use because anything else would be pointless

that's correct no matter how you slice it yes . going to a 3 inch after a 1 1/2 pipe is a waste of money you can throw as much psi at it as you want a 1 1/2 pipe can't handle even a third of what a three inch can

 

[combatwombat]

that's correct no matter how you slice it yes . going to a 3 inch after a 1 1/2 pipe is a waste of money you can throw as much psi at it as you want a 1 1/2 pipe can't handle even a third of what a three inch can

Well, I'm not sure what else to say other than that is not correct.

 

[combatwombat]

a 1 1/2 pipe can't handle even a third of what a three inch can

Ok, actually that part is correct, but it is not applicable to what I'm talking about and what @JesseMoreira06 needs to know to understand friction loss in their plumbing system.

 

[GBBUDD]

@Jhn whats your take on this not to put you on the spot but i know it's in your wheel house

 

[combatwombat]

@GBBUDD: Don't you run 3" lines in your own pond? I saw a photo of you washing pea stone with a 3" flex pvc hose?

I'm trying to figure out if we're arguing the same point here, because I'm baffled. Ponds are built every day w/ 3" pipe. I've never seen a pond pump or a skimmer that has a 3" outlet unless it was modified. Do you think it's pointless to use a 3" pipe on a pump with a 2" outlet?

One small restriction doesn't eliminate the benefit of a larger pipe. It just adds some friction to the overall equation. You wouldn't run 10,000 GPH through a 1.5" line, but a 1.5" outlet on a skimmer doesn't keep you from running 10,000 gph at all. It means you have to compensate for it somewhere else in the system. Like a bigger pipe!

It's just a matter of how much head pressure you're able/willing to deal with. Theoretically, if you have a strong enough pump, you could send 50,000 gph through a 1/2" pipe. Not really as the pipe would probably explode, but the physics allow it.

The restriction that an undersized fitting or inlet/outlet makes is not a showstopper. Seems that pretty much every pond over about 5,000 gallons would have at least one. They're just restrictions that increase the power needed to push the amount of water you want.

@JesseMoreira06: Sorry for hijacking your thread to argue about pipe fittings.

 

[GBBUDD]

@GBBUDD: Don't you run 3" lines in your own pond? I saw a photo of you washing pea stone with a 3" flex pvc hose?

YES that is correct. but the difference is my pump has a 3" inlet and a 3" output not a 1 1/2

Do you think it's pointless to use a 3" pipe on a pump with a 2" outlet?

YES aLL GOING TO A 3" IS GOING TO DO FOR YOU IS INCREASE HEAD"the amount of water the pump will have to push will double" yet the pressure reduces by more than half it can only push from the restrictions of a smaller pipe it can never give what the larger pipe is capable of AT THE SAME PRESSURES. COULD I TAKE A 1 1/2 " LINE separately pressurize it it to 3000 and get the same flow out of it that a 3 inch can at 40 spi i believe so but thats is only relevant to a point . Because you still only have the restriction of a smaller pipe at the start . Now fluid dynamics is an art all by it's self but having talked to engineers over the years and way to many of them, they factor in some ridiculous things like flex on a 15 foot WIDE concrete caisson. 50 feet deep. how much is a concrete cylinder going to bend REALLY. Can you increase the pressure of a 1 1/2 inch pipe to 3,000 psi and really push some fluid through it sure. are you getting again anything over a 3" nope throw the same 3,000 psi to a 3" and your pond will be empty in a minute.
U can certainly reduce from larger to small every day of the week you'll reduce flow and pressure each time you add another branch off the LARGER supply that's why we add ball valves to control who gets how much of that pressure and flow.

It's just a matter of how much head pressure you're able/willing to deal with. Theoretically, if you have a strong enough pump, you could send 50,000 gph through a 1/2" pipe. Not really as the pipe would probably explode, but the physics allow it.

yes we are talking the same animals but your increasing pressure to pipes the same pressure both fed through a smaller pipe will have the restrictions of the smaller pipe throughout the system . you gain nothing" if i took my 3" outlet and reduced it to 1 1/2 my pressure will skyrocket because my pump is being restricted is it still going to put out through the 1 1/2'' pipe the same as it were the three inch AT THE ORIGINAL PRESSURES "HEAD" no but . Thats where fluid dynamics come in, AND ONE OF THE MOST COMPLICATED ENGINNERINGs THERE IS. "sorry for caps its just me.''

YOU NEVER WANT to intentionally reduce a pipe inline and then step back up to the larger for no reason. you will severely reduce your flow . don't make it confusing,. To answer to the question by the post is if you have 1 1/2 inch as a feed from your pump stay with that size you get no benefit increasing the pipe size in our simple plumbing designs.

 

[combatwombat]

@JesseMoreira06: Please forgive us for derailing your thread. Stick with us. We're good, helpful folk here. Have you finalized your plan?

@GBBUDD: I copied our comments over here. Let's continue there so we don't run Jesse off into the sunset.

 

[JesseMoreira06]

No problem at all, I am actually enjoying reading it all.

 

[JesseMoreira06]

@JesseMoreira06: Please forgive us for derailing your thread. Stick with us. We're good, helpful folk here. Have you finalized your plan?

@GBBUDD: I copied our comments over here. Let's continue there so we don't run Jesse off into the sunset.

So I think Ive decided to go with a skimmer with pump that will connect to biofalls / bog with a T and two valves.

I havent decided yet , if I should in fact include a pressure filter as well since I already have one. Skimmer with pump to biofalls, then pump submerged bottom of pond (6-8" off the bottom) that connects to filter the to bog back to pond OR skimmer to bog and submerged bottom pump to filter to biofalls?

I dont think the pump would be strong enough to go from Skimmer with a T that connest to filter to bog and the other part to biofalls with two check valves? since my skimmer has a max flow rate of 5000gph

 

[Lisak1]

No problem at all, I am actually enjoying reading it all.

Well that tells us something about you! haha!

 

[combatwombat]

If you put a valve in front of it, you can install the pressure filter and just bypass it later if you want. You’d need one on it anyway if you split the flow as pressure filters put a lot of back pressure on your pump so you would need to fine tune where the water goes.

Most folks have moved on from pressure filters, though.

 

[Lisak1]

If I already owned a pressure filter, I'd use it. But I've yet to find one that has reviews good enough that I'd consider buying one.