Should I install a bottom filter?

[koikeepr]

This is to Dr.C's point. First of all, a true BD whether retro or standard should be gravity fed for the best efficiency. Perhaps that's what hasn't been made clear here, and why bthis is trying to feed it into a skimmer. Otherwise, it's more of a vacuum drain and not as effective.

Believe it or not, a 2" drain can do around 500gph, a 3" drain can allow around 1200 gph to gravuty feed through it and a 4" drain does about 4400 gph--so it's a significant difference between the two. If your pump can't keep up with that flow, you've got draw down. So you can see each inch of pipe width can add ALOT more to pass through it. If your pump can't keep up that pace, you've got a dilemma.

 

[DrCase]

We all know a larger pipe can move a lot more water than a smaller one.
And gravity will only work if the water has a place to go.
I just don't understand how the pond level could draw down in a closed system
When the pump runs the show
What ever it takes it puts back

 

[bthis]

You folks are great to take so much time explaining this to a poor semi-newbie.

I was leaning toward a 4-inch drain and/or 4-inch pipe to maximize the amount of detritus extracted through the bottom filter, because my Pecan trees drop so much. But at first I'll only have a 2400 GPH Fish Mate submersible pump. Maybe that's not strong enough to create flow through a 4-inch pipe?

I was hoping to use that one pump for both the skimmer and the bottom drain until I can get a Sequence or similar external pump (then use only that one pump). I see other installation photos online, and at least two skimmer manufacturers, who plumb the bottom drain into the skimmer. I learned today that Atlantic and Little Giant skimmers have cut-outs designed for that, and Atlantic even has a BD kit for its skimmer. But if it's a bad idea in practice, I need to figure out how it SHOULD be done.

Meanwhile, I'm confused about another concept: gravity-fed vs vacuum drain? Either one must be driven by a pump, right? The BD goes to a skimmer that contains a pump that lowers the water level, sucking water into the skimmer weir and the BD. Or, the BD runs to a settlement chamber, which also has a pump attached that lowers the water level, sucking water through the BD. In either case, the pump sends the output to my filters, then my upper falls, stream, and lower falls back into the pond. If those are vacuum drain setups, what's a gravity fed BD? And what's the difference between those two setups that would make the skimmer version not work?

Boy, I'm glad I didn't just start ordering parts, as my original plan was to do this over the holiday!

 

[koikeepr]

Ok. Hang on a second. I realize you keep saying bottom "filter" and I am thinking bottom "drain." Are we talking about the same thing?

If you you've got Pecan trees that drop a heap, you should be really thinking about a net over your pond.

And, yes, truly a BD is meant to work with a external filter and not an submersible. I assumed you had an external.

Gravity feeding means that your pump and BD and filters would receive water because they are below water line. You can also have a vacuum drain that would suck because the pump is pulling--these are not as efficient.

 

[bthis]

Ok. Hang on a second. I realize you keep saying bottom "filter" and I am thinking bottom "drain." Are we talking about the same thing?

If you you've got Pecan trees that drop a heap, you should be really thinking about a net over your pond.

And, yes, truly a BD is meant to work with a external filter and not an submersible. I assumed you had an external.

Gravity feeding means that your pump and BD and filters would receive water because they are below water line. You can also have a vacuum drain that would suck because the pump is pulling--these are not as efficient.

My bad--Bottom Drain, not Bottom Filter. Everything I am installing is at water level. The pump outlet(s) will take the skimmer and/or BD output to my filter, which is raised and gravity-feeds the falls and stream.

I do put a net up in the Fall, but it's a lot of trouble to do so again in the Spring for flower-dropping season. I have seven huge pecan trees, two right over my patio and pond. These big ol' fellows drop stuff all year round--leaves, small branches, bark and such all the time, assisted by the wind and the big, fat squirrels who plop half-eaten pecans in the pond, not to mention the occasional squirrel nest that blows down. So it's a continuing battle. If She Who Must Be Obeyed didn't have them under Her protection, I'd have a lot of squirrel stew and a lot fewer squirrels, but...

Gotcha about the external [pump-not filter] Now I'm confusing you! Sorry! Thanks for explaining.

 

[koikeepr]

Do you have the ability to dig a filter pit next to your pond so that you can have true gravity feeding for your pump, filter, etc.? Or does your property slope somehow so this equipment can sit below water line?

Flowers and floating debris can be handled by a skimmer. I have the large savio skimmer and it's great for leaves and such. As far as the nuts, I'd be afraid of them clogging things up. I really do think you should consider putting bird netting on a frame to help you make it very easy to move. One of our users recently did this and it looked great. I think it was D&RK.

A photo of your situation would really help us.

 

[bthis]

Let's see if I can figure out how to upload photos before I have to leave for the fireworks tonight. First, here's view of the pond from my patio. The lovely lady holding a seashell to her ear is the reason I got into ponding in the first place. My Sweetie Pie fell in love with the statue. Once we got her home she didn't look good just sitting on a rock, so I foolishly suggested I build a little basin to catch the flow, and we could hook her up to a pump. The rest is history. In those days I don't think there was such a thing as a disappearing fountain...

View attachment 3241

The falls underneath the mermaid is run by a separate filter with a small in-pond filter box, so if a pump fails the pond stays aerated and filtered until it's repaired or replaced. The falls is badly in need of re-building as you can see from the one jet that's streaming into the pond and the others that are barely flowing.

Here's the pond with the filter in the background, the upper falls, upper pond, stream, and lower falls. With the bamboo gone, I might convert the upper pond to a bog filter.

View attachment 3242

A closer shot of the stream. You can't really see it, but there's a cloud of bubbles at the bottom right from the venturi, which also sends a flow toward the deep end where the bottom drain would go.

View attachment 3243

Here's my filter--a 40-gal settlement chamber, a biofilter (brushes followed by a bag of potscrubbers followed by filter media), that flows to an upper falls. The brushes are needed because the flow is a little too fast through the SC, plus the occasional leaf falls into the SC. All of this was totally hidden by a decades-old stand of bamboo until last weekend when I chopped it down for the first time. I'm digging up as much of the root system as I can get to, and plan to kill it as it comes back over the next few years until it doesn't come back anymore. Bamboo, it turns out, can grow right through EPDM without even pausing to think about it. Had I known this eight or nine years ago I might have put the pond elsewhere, or opted for a cement version.

View attachment 3244

Here's my one remaining large koi in my Add-A-Sphere, which is terribly murky because I've been digging around in the stream and upper pond, stirring up muck. Had it been so murky when the Heron hit I might have more fish.

View attachment 3245

When I finish the re-build I hope to have all the rocks mortared in place, all of the liner and the upper falls better hidden, and a better filtration circulation with the skimmer and bottom filter.

 

[bthis]

Let's see if I can figure out how to upload photos before I have to leave for the fireworks tonight. First, here's view of the pond from my patio. The lovely lady holding a seashell to her ear is the reason I got into ponding in the first place. My Sweetie Pie fell in love with the statue. Once we got her home she didn't look good just sitting on a rock, so I foolishly suggested I build a little basin to catch the flow, and we could hook her up to a pump. The rest is history. In those days I don't think there was such a thing as a disappearing fountain...

View attachment 3241

The falls underneath the mermaid is run by a separate filter with a small in-pond filter box, so if a pump fails the pond stays aerated and filtered until it's repaired or replaced. The falls is badly in need of re-building as you can see from the one jet that's streaming into the pond and the others that are barely flowing.

Here's the pond with the filter in the background, the upper falls, upper pond, stream, and lower falls. With the bamboo gone, I might convert the upper pond to a bog filter.

View attachment 3242

A closer shot of the stream. You can't really see it, but there's a cloud of bubbles at the bottom right from the venturi, which also sends a flow toward the deep end where the bottom drain would go.

View attachment 3243

Here's my filter--a 40-gal settlement chamber, a biofilter (brushes followed by a bag of potscrubbers followed by filter media), that flows to an upper falls. The brushes are needed because the flow is a little too fast through the SC, plus the occasional leaf falls into the SC. All of this was totally hidden by a decades-old stand of bamboo until last weekend when I chopped it down for the first time. I'm digging up as much of the root system as I can get to, and plan to kill it as it comes back over the next few years until it doesn't come back anymore. Bamboo, it turns out, can grow right through EPDM without even pausing to think about it. Had I known this eight or nine years ago I might have put the pond elsewhere, or opted for a cement version.

View attachment 3244

Here's my one remaining large koi in my Add-A-Sphere, which is terribly murky because I've been digging around in the stream and upper pond, stirring up muck. Had it been so murky when the Heron hit I might have more fish.

View attachment 3245

When I finish the re-build I hope to have all the rocks mortared in place, all of the liner and the upper falls better hidden, and a better filtration circulation with the skimmer and bottom filter.

 

[bthis]

Do you have the ability to dig a filter pit next to your pond so that you can have true gravity feeding for your pump, filter, etc.? Or does your property slope somehow so this equipment can sit below water line?

In answer to your question, I _could_ dig another pit, but I'm wondering if anyone has any experience with the bottom drain flowing into the skimmer as done in Atlantic's and Little Giant's designs?

 

[bthis]

Do you have the ability to dig a filter pit next to your pond so that you can have true gravity feeding for your pump, filter, etc.? Or does your property slope somehow so this equipment can sit below water line?

In answer to your question, I _could_ dig another pit, but I'm wondering if anyone has any experience with the bottom drain flowing into the skimmer as done in Atlantic's and Little Giant's designs?