Mechanical Filtration - Skimmer vs Waterfall Filter


ATP

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I am in the planning stages of a pond I hope to start building in the spring. At the moment the pond will be in my front yard, right of my the paver walkway going to my front door. I have the space to add a 10 x 15 pond with a small water feature. The yard is level so i dont want to build it up too much and thinking just a small drop into the pond. I will be adding various plants, lillies and probably starting with comets to see how they do from a predator standpoint. I will be adding shelves and rock to completely hide the liner.

Due to wanting to keep it somewhat confined to a "smaller area" I have been looking at the skimmer box / waterfall filter box combos. I totally get the importance of the skimmer to remove large debri and some mechanical filtration, before it can decompose on the pond bottom. Where I am getting hung up is the need for the large water fall filter boxes that seem to have the primary purpose of bio-filtration. Most likely I will need to bury one of these units at least halfaway below the surface in order for a more natural look.

In a pond with tons of rock and not just the bare liner isnt there plenty of surface area for nitrifying bacteria to colonize? What is the purpose of needing additonal biological filtration in the waterfall filter or "Bio Falls" as on manufacturer calls it? Or, is it really just an additional mechanical filtration based upon the media you add to it?

I really like the idea of the intake bay/zero edge and bog filtration just dont know if i want to dedicate the space these need to function properly.
 
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brokensword

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I am in the planning stages of a pond I hope to start building in the spring. At the moment the pond will be in my front yard, right of my the paver walkway going to my front door. I have the space to add a 10 x 15 pond with a small water feature. The yard is level so i dont want to build it up too much and thinking just a small drop into the pond. I will be adding various plants, lillies and probably starting with comets to see how they do from a predator standpoint. I will be adding shelves and rock to completely hide the liner.

Due to wanting to keep it somewhat confined to a "smaller area" I have been looking at the skimmer box / waterfall filter box combos. I totally get the importance of the skimmer to remove large debri and some mechanical filtration, before it can decompose on the pond bottom. Where I am getting hung up is the need for the large water fall filter boxes that seem to have the primary purpose of bio-filtration. Most likely I will need to bury one of these units at least halfaway below the surface in order for a more natural look.

In a pond with tons of rock and not just the bare liner isnt there plenty of surface area for nitrifying bacteria to colonize? What is the purpose of needing additonal biological filtration in the waterfall filter or "Bio Falls" as on manufacturer calls it? Or, is it really just an additional mechanical filtration based upon the media you add to it?

I really like the idea of the intake bay/zero edge and bog filtration just dont know if i want to dedicate the space these need to function properly.

okay, some points to also consider and commentary on what you're posting about.

First, I'd definitely make sure you can HAVE a pond in your front yeard. Some zoning codes/home owner associations won't let you. Then there's the issue of how deep; some zoning makes you fence the whole thing in if a certain depth. So, double check you don't waste your time. You might end up putting it in your backyard instead.

Two; depending on what type of fish/fish load you are looking at, I'd seriously consider what type filtration you want. A lot of GPF uses bog filtration (do a search; lots of data and info for you to consider) for ease of mainenance (zero) and effectiveness value based on cost. It can also add to your landscape while doing the filtering for you. A bog filter is your biofilter, the same you're looking at re at the waterfall. A waterfall filter has a disavantage in that it's not as easy to clean, and it's typically very small (capacity, therefore small effect bio-wise).
For instance, an effective BOG filter should be 30% of your pond. Consider how much manufactured/bought volume/capacity you'd need as comparable).

Too, you're going to bury a large bio-waterfall filter; why not realize you GET a water fall WITH a bog filter and kill two birds with one stone? Doesn't mean you can't also have more waterfalls, but you take away some complexity of your waterfall build then.

You DON'T want your pond edge to be LOWER than your surrounding grade; runoff is a huge no no and can affect your water immensely. You'll want to berm it up somehow to avoid this possibility.

Okay; biofilteration 101; your UW surfaces will indeed be colonized by the 'good' bacteria, but when comparing THAT surface area to what you'd get with a bog (short description; a box full of pea gravel in which water is pumped/forced from bottom to top, giving MORE water a chance to be 'denitrifyied' than just hopiing your circulation moves the water colum TO your UW surfaces.) isn't close; There's a LOT more area on a huge amount of small stone than on one flat rock surface in your pond.

The biofiltering is not a 'gimmick', it's the sole reason (within reason) you'll be successful with a pond and fish in the end. A bog will also help keep free floating algae at bay, along with a generous use of floating plants. Again, other benefits but yoiu can ask those questions later. A bog CAN filter mechanically but that's not it's main function and should not be used this way; you'll have clogging and more issues than you want. You CAN get/make a pre-bog filter for such purposes, again a question for later.

A skimmer/negative edge/intake bay are all NOT necessary but for certain ponds, can be a huge help. Depends a lot on your surroundings (i.e. trees? winds that blow across your yard/pond etc). They do reduce SOME decaying debris but not all, realize this. Most are for keeping the surface clear and clean visually. You'll probably still have to do some manual work on the bottom if you get any large amount of acculation. With a balanced system and not a lot of surrounding trees, imo, you can ditch all three, and we have more than a few ponders here that show little to no decay on their pond bottom over time.

So all in all, I'd reconsider your pond footprint from 'small' to something including a bog, simply because you'll never regret it. Think of it as a garden you'd have plants in anyhow, but these plants are water-specific and are in symbiosis with your pond, no matter what size pond you end up with.

Hope this helps!
 
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ATP

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okay, some points to also consider and commentary on what you're posting about.

First, I'd definitely make sure you can HAVE a pond in your front yeard. Some zoning codes/home owner associations won't let you. Then there's the issue of how deep; some zoning makes you fence the whole thing in if a certain depth. So, double check you don't waste your time. You might end up putting it in your backyard instead.

Two; depending on what type of fish/fish load you are looking at, I'd seriously consider what type filtration you want. A lot of GPF uses bog filtration (do a search; lots of data and info for you to consider) for ease of mainenance (zero) and effectiveness value based on cost. It can also add to your landscape while doing the filtering for you. A bog filter is your biofilter, the same you're looking at re at the waterfall. A waterfall filter has a disavantage in that it's not as easy to clean, and it's typically very small (capacity, therefore small effect bio-wise).
For instance, an effective BOG filter should be 30% of your pond. Consider how much manufactured/bought volume/capacity you'd need as comparable).

Too, you're going to bury a large bio-waterfall filter; why not realize you GET a water fall WITH a bog filter and kill two birds with one stone? Doesn't mean you can't also have more waterfalls, but you take away some complexity of your waterfall build then.

You DON'T want your pond edge to be LOWER than your surrounding grade; runoff is a huge no no and can affect your water immensely. You'll want to berm it up somehow to avoid this possibility.

Okay; biofilteration 101; your UW surfaces will indeed be colonized by the 'good' bacteria, but when comparing THAT surface area to what you'd get with a bog (short description; a box full of pea gravel in which water is pumped/forced from bottom to top, giving MORE water a chance to be 'denitrifyied' than just hopiing your circulation moves the water colum TO your UW surfaces.) isn't close; There's a LOT more area on a huge amount of small stone than on one flat rock surface in your pond.

The biofiltering is not a 'gimmick', it's the sole reason (within reason) you'll be successful with a pond and fish in the end. A bog will also help keep free floating algae at bay, along with a generous use of floating plants. Again, other benefits but yoiu can ask those questions later. A bog CAN filter mechanically but that's not it's main function and should not be used this way; you'll have clogging and more issues than you want. You CAN get/make a pre-bog filter for such purposes, again a question for later.

A skimmer/negative edge/intake bay are all NOT necessary but for certain ponds, can be a huge help. Depends a lot on your surroundings (i.e. trees? winds that blow across your yard/pond etc). They do reduce SOME decaying debris but not all, realize this. Most are for keeping the surface clear and clean visually. You'll probably still have to do some manual work on the bottom if you get any large amount of acculation. With a balanced system and not a lot of surrounding trees, imo, you can ditch all three, and we have more than a few ponders here that show little to no decay on their pond bottom over time.

So all in all, I'd reconsider your pond footprint from 'small' to something including a bog, simply because you'll never regret it. Think of it as a garden you'd have plants in anyhow, but these plants are water-specific and are in symbiosis with your pond, no matter what size pond you end up with.

Hope this helps!
Wow, thanks for the detailed response!

Good idea, I will check my local zoning regulations. I live outside of a village in a town. I have an acre of land with the larger portion being in the front. There are many residents that have natural earthen ponds much larger than the one I am proposing in their front yards, so didnt think mine would be an issue.

Part of the reason for wanting to put it in the front is i feel there will be less chance of predators going after the fish since it will be much closer to the house. Right off my back door is an inground pool and I would need to put a pond behind the pool against a woodline with a small stream. I am not opposed to putting it in the back but my decision to put it in the front is heavily driven around predator access to the pond. Maybe, I am overthinking this and either location will still offer the same opportunity for potential predators?

I do really like the idea of the bog and have not ruled it out. I have spent some time on bogfiltration.com and definately see the benefit over other options out there.

I have very few leaves (more in the back than front) but i do get some strong winds. Would the skimmer box feed the bog or are there betters ways (prefilter) to return water to the bog?

I am open to any ideas and not set on any one design. I would like to keep the pond around 10 x 15 to keep the initial and ongoing costs manageable.
 
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Good infö already shared. If you compare the filtration you can get from a bog to a filter box, you'll find that even a small bog will be far more efficient at providing biological filtration.

As for mechanical filtration you could consider a negative edge that drops into a pondless type set up. You'll see this style of pond more and more often being built by the professional builders.

Edited to add: as for pond location - you should always consider viewing areas when you build a pond. Do you sit in your front yard? Will you be able to see it from inside the house? Predator concerns would fall far down on my list of consideration when deciding on the best spot for a pond.
 
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@ATP
I built my pond right in the front also so I could view it sitting on our front deck. Don't fool yourself into thinking that it being close to your house in front will stop any predators. It does not, take my word for it. I fought w/heron and raccoons and tried everything under the sun to stop them from coming into my pond. The only thing that ever worked is my raised up high wide weave fishing net that attaches to a short wire fence. It is totally enclosed and now critters can't get in........................knock on water,lol!

IMG_5317.JPG
 

ATP

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Good infö already shared. If you compare the filtration you can get from a bog to a filter box, you'll find that even a small bog will be far more efficient at providing biological filtration.

As for mechanical filtration you could consider a negative edge that drops into a pondless type set up. You'll see this style of pond more and more often being built by the professional builders.

Edited to add: as for pond location - you should always consider viewing areas when you build a pond. Do you sit in your front yard? Will you be able to see it from inside the house? Predator concerns would fall far down on my list of consideration when deciding on the best spot for a pond.
We dont sit in the front but we are out front quite frequently. It would be viewable from multiple windows and anyone coming to the house would walk right by it. In the backyard it would go behind the pool area and be further from the house. The backyard has a natural slope down to a flat area which might work well for a raised bog with a small stream.
 

brokensword

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Wow, thanks for the detailed response!

Good idea, I will check my local zoning regulations. I live outside of a village in a town. I have an acre of land with the larger portion being in the front. There are many residents that have natural earthen ponds much larger than the one I am proposing in their front yards, so didnt think mine would be an issue.

Part of the reason for wanting to put it in the front is i feel there will be less chance of predators going after the fish since it will be much closer to the house. Right off my back door is an inground pool and I would need to put a pond behind the pool against a woodline with a small stream. I am not opposed to putting it in the back but my decision to put it in the front is heavily driven around predator access to the pond. Maybe, I am overthinking this and either location will still offer the same opportunity for potential predators?

I do really like the idea of the bog and have not ruled it out. I have spent some time on bogfiltration.com and definately see the benefit over other options out there.

I have very few leaves (more in the back than front) but i do get some strong winds. Would the skimmer box feed the bog or are there betters ways (prefilter) to return water to the bog?

I am open to any ideas and not set on any one design. I would like to keep the pond around 10 x 15 to keep the initial and ongoing costs manageable.

as the others have pointed out; no matter where you put it, if you have predators, they will find it. Just a matter of time. I have a customer who put one right in front, by his porch. Not large, can hardly see it, but a heron has found it 3 times now in 5 years. And no matter how much I tell him he could easily net the pond when he's NOT there and slip it off when he is, well, stubborn is a word some peeps know very well. So, I'm not saying front or back--as others have noted, I'd put it where you'll most see it and most appreciate it. Zoning and all that was just so you're not surprised by any city ordinances. If others have one in their front yard, as you said, probably not an issue.

DO search the threads HERE for bogs as we've done a lot of experimentation and experience. And of course, ask questions re bogs to your heart's content.

If you worry re leaves, think about a leaf net in the fall; usually the weave is smaller; will save you lots of labor getting them out later.

We DO have a saying around here, so consider this; LPS is REAL! What's LPS you say? Larger Pond Syndrome.

Can't say I didn't warn ya!
 

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View attachment 146298@ATP
I built my pond right in the front also so I could view it sitting on our front deck. Don't fool yourself into thinking that it being close to your house in front will stop any predators. It does not, take my word for it. I fought w/heron and raccoons and tried everything under the sun to stop them from coming into my pond. The only thing that ever worked is my raised up high wide weave fishing net that attaches to a short wire fence. It is totally enclosed and now critters can't get in........................knock on water,lol!

View attachment 146299
Yikes! yes that is one of my concerns. Your pond is pretty deep, does that help with the predators? I was going to build a cave in the deep section, wondering if that will even help.

Did you have any concerns as far as town zoning laws with building it in the front?
 

brokensword

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Yikes! yes that is one of my concerns. Your pond is pretty deep, does that help with the predators? I was going to build a cave in the deep section, wondering if that will even help.

Did you have any concerns as far as town zoning laws with building it in the front?

this is the thing; deep water CAN help, fish caves CAN help, but if you've ever watched a heron, you'll know the definition of patience. There's a saying; when a heron finds your pond, they don't leave until it's been emptied. And they say that for a reason! A net is the only sure way of keeping predators (that are not bears, moose, cougars) out of your pond. For those three listed, good luck!
 
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Here is my experience, I hope it might help you decide which way to build your pond.

Both of my ponds setup use bog filters. I would not build one without it :)

My first pond, I made this skimmer box. It was too small. I have to cleaned out the leafs too often. The water level also have to be on the same level as the pond, so it not as efficient in getting rid off all the floating debris.
20191124_170921.jpg


My new pond, I went with negative edge and cistern. I have a big laundry basket to catch all the leafs. The cistern is big and covered, so no leafs can get in. The water surface is very clean, and I only have to emptied out the basket if too much flow is restricted (so it depends on how much trees you have around). I am really liking this design. The water level in the pond is always the same. I only have to re-fill when the cistern water is getting low due to evaporation and garden watering.
20211215_182142.jpg
 

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Yikes! yes that is one of my concerns. Your pond is pretty deep, does that help with the predators? I was going to build a cave in the deep section, wondering if that will even help.

Did you have any concerns as far as town zoning laws with building it in the front?
Don't tell anyone but the county doesn't know anything about my pond. We are not in the city so perhaps that is why they haven't been poking around here.

Depth did not keep heron away when I had no net. They just stood and waited. Raccoons went in the pond but not sure if they got any fish as they don't dive I don't think. They did make a mess in there tho toppling plants over and knocking rocks off the ledge.
You can't leave even one small skinny space w/o protection as something will weasel it's way in there if you do eventually.
This photo was before I had the net up but I did have the wire fence around it. I watched him squeeze right through a space in the wire. After that I put extra wire on the fencing and also added the netting.
IMG_1267.JPG


This below is after I put the net up and enforced the fencing w/added wire. He can't get in there now. He looks mad :smuggrin:
IMG_8704.JPG
 
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Don't tell anyone but the county doesn't know anything about my pond.

Some questions are better left unasked. Or as they say "Sometimes it's better to ask forgiveness than permission".

We aren't supposed to burn yard debris in the village limits. But we can have bonfires if the fire is off the ground. Makes so much sense. So we use our fire pit and burn "wood" we "gather" from our yard. Everybody is happy.
 

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Some questions are better left unasked. Or as they say "Sometimes it's better to ask forgiveness than permission".

We aren't supposed to burn yard debris in the village limits. But we can have bonfires if the fire is off the ground. Makes so much sense. So we use our fire pit and burn "wood" we "gather" from our yard. Everybody is happy.
That is what i am afraid of. Sometimes when you ask you get an answer..lol. I have reviewed the building code for my town and it calls out "Swimming Pools" as needing permits, but it seems if dont intend to use it for swimming then no permit required. I do live in more of rural setting and many people in my town have actual eathern ponds in their front yards with no fence and larger and deeper than what would be allowed if it were for swimming. My fear is I call and get someone that doesnt know the code and they tell me its required when its actually not.
 
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I write knowing the GPF is usually a pretty friendly bunch and I'm counting on you to stay so! I'm far more concerned than most people on the issue of water/ pond safety and ask for your understanding. I am not trying to preach or criticize.
Ponds can be a risk for kids (and liability for the owner), and in my opinion those that are visible from the road or casual visitors to the house may be more so, as they are easy to get to (and in). I'm not quite thinking of kids as little predators (but then again...)
Many years ago, friends of our family lost a little girl to drowning. A canal was not fenced from the yard they were visiting, and the little explorer slipped away unnoticed, and in less than 5 minutes, she drowned. I don't share this to open a debate over right/ wrong or local rules, but rather to ask and remind we ponders to keep safety in mind. I know there is open water everywhere and most pond owners have never had an accident, for which we are all thankful, but let's be think-ful, too. Whew. Sorry for sad topic on a Monday morning.
 
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I agree with you @SarahT that we all need to be cautious and thoughtful when we add an "attractive hazard" to our yards. But I will also add that I have personally known two families who lost children to drowning - one was in a bucket of water, the other was in a bathtub. Both were terribly tragic and sad, but I wouldn't advocate to change how, when, or where we use buckets or bathtubs as a result.

I think there are two issues: 1. the recognition that young children need to be watched at all times and 2. the understanding that no matter how careful we are, life is full of hazards and sometimes unfortunate accidents happen.
 
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Drowning in a bucket that had to be unbearable you can't protect from everything. A tub unfortunately is a common hot spot and as a builder i do know a couple that have stopped installing tubs in there homes. think about it the amount of times a adult or adolescent BATHES is absolute minimal. With the new rain shower heads i have seen the kids love those almost as much as floating the rubber duck in the tube. THE BABIES HECK I PREFER THE WASH basin on the counter.
All around my pond is angled rocks there's no vertical walls so even if one can't swim they should be able to get a footing. There's obviously no guarantees But we do have a fence and or netting barriers to keep little ones out
 

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I also have an inground pool and we have worked hard to keep the kids safe. Luckily my youngest is now 5 and is already a decent swimmer. I would not have thought about building a pond any earlier than this spring due to his age.

My front yard is a good distance from the road and being in a rural setting there are no kids that would be able to safetly walk on the road alone and into my front yard. Luckily the neighbors dont have any young kids anymore and the safety of anyone visiting with young children will be our first priority. The way the houses in my neighborhood are set up, the risk of having it in the back may be greater than the front of the houses, given that is where any visiting children play.

I do plan on not making it more than 3 ft at the deepest with shelves that can be used as step should someone accidentally fall in.
 
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Thanks for having thought it through and taking the time to let me know. I'm glad it will work out safely for everyone, and I'll keep my fingers crossed that no predators coming a'calling. I'm sure your pond will be gorgeous. Post pictures as you go along with your project.
 
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