Retro bottom drain question

[koipondpeppy]

Hi there. I'm new. I have a 6,000 gallon pond with koi that works great with a bunch of filters and a pump fed retro bottom drain.

We built a new house down the road so I have to build a new pond there this summer.

I want another retro bottom drain the reason being that in the winter, I remove it and cap off the 3" pipe that goes through the liner and to the pump. I have to cap all pipes off inside the pond so they don't freeze.

I know people say keep the pump on but when the power goes out then what? I prefer to cap off the pipes for winter and not worry about it.

Does anybody know how much flow to expect from a retro bottom drain through a 4" pipe into a radial flow separator?

Thanks a bunch!

 

[GBBUDD]

Many here don't feel a bottom drain is worth it . i however like them . But here's a thought for you I imagine you know what the snorkel and centipede is .Well i have thought if i was to do it again i would trench out the bottom like you would for a bog and set the centipede in the trench after the liner is placed and put some 2 to 3" stone around the pipe to where you are now flush with the bottom of the pond. Key here is NO hole in the liner. Do the same with the snorkel so that it to is set back from the majority of that wall again no holes in the liner and make a mound to hide the pipe as it comes up over the edge of the pond . THROW in your ball valve in below the water line oh and i would look at using 3 or 4" flex pvc not the reinforced like a pool vacuum hose but the smooth type.

 

[Ronfire]

My bottom drain has a valve on it inside a drum 2' below grade so it does not freeze. I can then drain all the lines down to that level and add insulation into the drum to help keep in the ground heat. The pipes into my bogs go over the top so they do have water in then to the level of the bogs. I was concerned about these ABS pipes but they wintered well with no cracks and 10" of ice. I think the pressure of the ice outside ballances the inside pressure to stop the pipes from breaking ( I hope).

 

[koipondpeppy]

Many here don't feel a bottom drain is worth it . i however like them . But here's a thought for you I imagine you know what the snorkel and centipede is .Well i have thought if i was to do it again i would trench out the bottom like you would for a bog and set the centipede in the trench after the liner is placed and put some 2 to 3" stone around the pipe to where you are now flush with the bottom of the pond. Key here is NO hole in the liner. Do the same with the snorkel so that it to is set back from the majority of that wall again no holes in the liner and make a mound to hide the pipe as it comes up over the edge of the pond . THROW in your ball valve in below the water line oh and i would look at using 3 or 4" flex pvc not the reinforced like a pool vacuum hose but the smooth type.

Thanks for the info GBBUDD!

I did a semi-trench for the current pond's retro bottom drain (really a vacuum bottom drain) but stuff lays in the trench. I don't have stone around it because I remove the whole thing for winter and cap off the 12 inches of pipe left inside the pond. The pipe goes through the liner about 18" under water.

But anyway, I need to know how many gph gravity flow I'll get out of a 4" pipe so I know how many radial flow separators I'll need to feed from the retro bottom drain.

Thanks for the tips!

 

[koipondpeppy]

My bottom drain has a valve on it inside a drum 2' below grade so it does not freeze. I can then drain all the lines down to that level and add insulation into the drum to help keep in the ground heat. The pipes into my bogs go over the top so they do have water in then to the level of the bogs. I was concerned about these ABS pipes but they wintered well with no cracks and 10" of ice. I think the pressure of the ice outside ballances the inside pressure to stop the pipes from breaking ( I hope).

That is a great idea you had there Ronfire! I just don't trust a bottom drain hole for myself. I don't mind a hole in the side for a retro (vacuum) bottom drain but a hole way down there in the bottom is too scary, lol.

Would you have any idea how many gph gravity flow I'd get from a 4" pipe out of a retro bottom drain?