Can you help me understand bottom drains?

[Waterbug]

What I meant was if you were to re-route the discharge from that pump to try and drain the pond, the pond could only drain to the bottom level of that outlet pipe coming from the bottom drain and that's it. You couldn't drain the pond completely, although I'm pretty sure the water level would go down a little more than "a hair".

I see. Yes, a drain leg would have to be added.

 

[shanezam203]

Only one that I can think of,,,, it's easier.

The easiest thing, and the most common practice with backyard ponds is to put in submersible pumps. Not very sophisticated, but it will pump ya wada fo ya.

Can I get away with putting a submersible 4000 gph pump at the deepest part of each Leg and have each flow back into the back corner of the pond through filtration & the water fall?

 

[Mucky_Waters]

You might be able to get away with it if you do it at night when nobody is watching. h34r:

Seriously, you can do what ever you want, it's just that some circulation and filter systems work better than others, and/or are easier to maintain. There are pros and cons to every system, but before you can ever decide what you'll need you need to figure out what your pond is going to be.

Large population of big koi? You should think about bottom drain and sieve filter.

Maybe just a few goldfish? Submersible pump and Skippy will do.

Water garden? You may not even need any sort of filteration at all.

 

[shanezam203]

I'd like a few large 12" + koi and I will pry be constantly adding to it...

 

[riparks]

I have a 4" bottom drain and I am very pleased with it. I have an external pump with a priming pot/straining basket that is not gravity fed because when we were rebuilding the pond last year, my husband refused to bury it. The bottom drain and skimmer are plumbed separately and attach before the pump. My pond is a little over 3000 gallons and rectangle shaped (can't remember the exact dimensions.) Because of the shape, decaying leaves and muck get trapped in the corners of the pond, I use a brush on a pole and push the gunk into the bottom drain and it gets trapped in the priming pot/straining basket. All I have to do is turn off the pump, rinse the straining basket and the gunk is taken care of. I have not had any problems with pipes clogging.

 

[shanezam203]

Yes I have one pump that just runs that "spray bar" type thing on the end, helps push all of the leaves and stuff toward the skimmer at the other end of the pond.

Forgive my ignorance but for a 4" drain you have a 4" pvc returning to the pump right? I thought most pipes were 2".
Does the Pump have a 4" inlet or are you converting 4" to 2"?

 

[Waterbug]

If you connect a pump directly to a BD you do have to reduce to the pump's intake. For backyard pond type pumps 2" is the max intake I've seen.

It's a big world. You can certainly find people who think pretty much anything is a good idea. And that thing may well work just great for them, using their definition of "works great". Whether their definition also fits yours is a personal matter.

 

[shanezam203]

So that 4" bottom drain is 4" at the top, but the outlet is 2 inch or it's 4 and needs to be reduced on my own to 2...?

Thanks for all the help,
Shane

 

[riparks]

The diameter of the the bottom drain and outlet are 4" and my husband reduced the outlet to 2". I did not adjust the pump's intake and it is doing exactly what I want it to do.

I do not have a scientific mind and frankly don't understand flow rates, etc.. What I do know is that my pond is crystal clear, my water tests are perfect, and the fish and plants are thriving. That's good enough for me.

I am certainly not a pond expert, but if someone asks a question that I can answer based on personal experience, I try to answer. It's up to the person asking the question to decide if it's good advice or not.

 

[Waterbug]

So that 4" bottom drain is 4" at the top, but the outlet is 2 inch or it's 4 and needs to be reduced on my own to 2...?

Yes, basically. It varies drain to drain but basically the first opening, where water first goes in is wide, like 6-12". The bottom or side of the drain then has an opening that is generally 2", 3" or 4". Some drains handle either 3" or 4". From the drain to the pump a 3" or 4" pipe is run. At the last possible point it would be reduced to whatever the pump requires.

It's cheaper to place the reducer at the drain and then run a smaller pipe from the drain to the pump. And it is not uncommon for first timers to do this. It works great for weeks, months, even years. Then they get a clog which is almost always going to be at the reducer. Clearing a clog at the drain is way more difficult than clearing it 4" inches from the pump strainer. And at some point the owner gets a little tired of clearing clogs and now that they have a problem they decide to do some research and fine that a gravity flow would be way better. With the reducer at the pump the conversion to gravity flow is pretty easy. If the reducer is at the drain the pipe under the pond will be undersized for a gravity flow and they're screwed. A $20 job turns into a $1000 job.

Disclaimer: Just because I explained how to connect a direct suction drain doesn't mean I think it's a good idea. Gravity is far superior but it does take a little bit of research and understanding.

Here's some good info imo.