[Ax Man]

Hi all, I have been enjoying this site for a couple years, and value the material/ advice here.
Iv'e been landscaping about 20 years, self employed, and come from a farm upbringing and natural resources education in college. My wife and I have built a nice small business in a rural area. Of course like all of you I suppose I have looked over ADI's catalogs, and I went 1 step further and attended a build a pond day. We have a client with an earthen, spring fed pond. It's approximately 20X30, ovalish, and maybe 4 feet in the center.
When I first viewed the property, it was covered in watermeal. I refered them to a local applications business who wiped it out for a nice sum.
At the same time, I gave them a long term solution Ala' Eco system.
Filtration/Waterfall to aerate, and plants to use the excess nitrate.
So now after a year and a half of paying the apps guy to kill weeds and algae blooms they are ready to buy in.
I plan on building a bog filter at the Southeast end, to make use of the prevailing wind, and try to skim off surface debris. The water level is said to fluctuate some, (though I have only seen maybe 6 inches of change in 2 seasons)
Have any of you built some thing like this?
My plan is to dig the hole, line it, construct my wet well of corrugated pipe, fill with rock, then break through to the pond with a lined channel of maybe 15 inch depth.
I think if I have it appear as a stream/ outlet and then fill the margins with plants It will serve my porpose.

At the top of the slope (maybe 5 feet) build another planted bog, with stream outlet and waterfalls to the pond, travelling in a north west dirrection.
My question is mostly on the effectiveness of the pond level bog, with a 4500 gph pump. Will it skim the surface too?
Sorry for the cafineated post...

[waterfall larry]

when you say line it are you thinking of epdm rubber?

i doubt if a 4500 gph pump will skim a 20 x 30 foot area. Cal pumps makes a 10,000 gph torpedo pump and it can be found on the internet for $250 to $300 so it doesn't make sense to pay the same for a smaller pump. The biggger the pump the more water it pulls in the more water it pulls in, the more suction it creates.

if you are worried about strong enough water currents you can increase this by the current created by the waterfall. place the waterfall across the pond.

[Ax Man]

Yes I am going to use rubber for the liner. the strem will head up wind and hopefully give the pond a slight swirling current to pull those leaves and dust in.
I'll search Cal pumps and see what I find.
Thanks!

[Stonehenge]

I'm hoping someone else can chime in on the skimming issue, because with a bog setup, skimming just doesn't seem to happen, and floating debris just finds it's way to the shoreline (which isn't so bad if there isn't much debris). And with varying water levels, if you set up a skimmer box and separate pump, a dry spell for that pond could mean you burn out the pump in the skimmer box.

There might be some other slick solution to this, but I don't know about it.

Re: pump size - the Cal pumps are nice - big water volume for little money, but with a bog I don't know if lots of flow is required or even desired. I'm not familiar enough with bogs to know for sure.

[Ax Man]

Thats what I was thinking. A 4500 pump, cross flow from stream to bog, and hope the leaves and such are consolidated for easier clean up.
The pond is located on a hill with trees nearby but not directly over. So what gets in there is carried by the wind.
Well if it hasn't been done yet, then I'll be the one to let you all know how it works LOL
Thanks!

[waterfall larry]

The world of water feature building is terribly polluted with all sorts of people running around spouting all sorts of ideas and making it seem like they are factual. I listen to all the theories and then try them out in the real world. If the theory proves true and proves to be something necessary to do then I adopt it. If I can’t see proof with my own 2 or 4 eyes in real life, I put the theory in my theory file. We all have to be concerned about separating the facts from the fiction. One of the biggest fiction areas is filtering or cleaning the water.
There are a dozen and one ways to filter the water. And there is some thought that you don’t need any filtration system. Whether or not you need any filtration depends on who you are and the type and size of your pond. Believe this though, the smaller the pond the more maintenance is needed. If you have koi or a lot of fish, filtration is necessary. If you have an earthen pond and a larger one, filtration may not be necessary at all. The theory is that a balanced eco system, i.e. fish, plants, aeration and beneficial bacteria, in the pond will reduce or eliminate the need for maintenance and filtration. If this happens great but I am still going to make some provision for filtration.

Bog filters aren’t known for skimming the surface debri. I am not real familiar with bog filters because I am more of a skimmer guy. I guess the theory is that bog filters build beneficial bacterial which cleans the water. In the real world, I have had to drain too many ponds and manually remove built up leaf litter and gunk to believe that bog filters are 100% fool proof. In some cases they may be but then in some cases they may not be. Either way a bog filter is a good bit of work and a lot of materials which leads to a greater cost to the customer. First there is excavation time and then cost for underlay and liner and then the cost of gravel or whatever to fill in with. This ends up being a good bit of cost. So the bog filter people will have to prove to me that bog filters are 100% fool proof and less expensive. They will have to prove to me that leaves and debri will never build up so much that manually removing debri is necessary.

It is possible to have both a bog filter and a skimmer. To do this though, you need 2 ponds an upper and lower. The upper pond is your bog filter and the skimmer goes in the lower pond.

While I am a skimmer guy I am not going to run around and say that skimmers are 100% fool proof. Yes they are a lot less expensive. Only a bucket filter is less expensive than my self made $20 to $40 skimmers. Bog filters are a lot more expensive. So are bead filters and vortex filters and uv lights. For a skimmer to work correctly several things have to be done correctly. The pond has to be the right shape, the amount of surface area, the placement of the waterfall / stream and the placement of the skimmer, the size of the pump, the size of the skimmer chamber can’t be too small for the size of the pump nor can it be too big for the size of the pump and finally the size of the opening in the skimmer chamber has to be correct. There is a sure fire way to test the skimmer after it is installed and the pond filled. Take 3 leaves and place them on the surface of the pond 5,10, and 15 feet from the skimmer. If the skimmer doesn’t suck in the 5 foot leaf and you just charged the customer for a $300 professionally made skimmer box, plus installation labor – well that wasn’t a good thing to do.

A skimmer is the only filtration method that takes a preventative approach. An ounce of prevention is worth a pound of cure. All other filtration methods deals with the problem after it happens and hope that the cure is sufficient or greater than the illness.

Given the prevention approach and lower cost, there are a lot of good reasons to become a skimmer guy and learn how to design things to produce effective skimmer filtration.

[trees]

I've used both bog filters and skimmers in most of the ponds I've built over the last 5 or 6 years.

Skimmers are primarily mechanical filtration. That is, they remove surface debris before it gets a chance to become muck. They work great and I rarely will do a pond without one.

A bog filter is basically a mini swewage treatment plant and serves as the best biological filtration you can get. They provide a tremendous amount more filtration than "biofalls" and other such things and eliminate the need for trying to hide those monstrosities. It can be set up as it's own pond, but I prefer to have it integrated into the main pond itself, where it can be an attractive planting space.

Basically, with a bog filter, the rule is that it should be 10% of the surface area of the pond. The bog itself is 12" deep and runs on its own pump, which is located in the deepest part of the pond (Titan pumps are best for this -- real workhorses, draw a tiny amount of amperage and last a long time). Build a retaining wall for the bog wall and backfill it with foam. Run the flex pipe from the "trash" pump to form a spiral in the bottom of the bog, cap it and put a bunch of 5/8" holes in it. Cover with gravel and plant bog plants directly into it. The bog can be set just above or below the water line depending on the look you'd like. Maintenance on these is actually pretty minimal (provided they keep up with bacterial treatments and other general maintenace tasks, of course). Detail the plants when needed, clean the pump housing a few times a year and (here's the hard part) scoop out all the gravel, rinse, and divide plants every 3rd year or so (great added maintenance dollars).

The bog filter / skimmer setup has worked great for me over the years. The bog keeps all the nasty waste nutrients out of the water, reducing algae growth, and the skimmer helps to keep the pond free of debris. Ponds can be a lot of maintenance, but this setup has been great for helping to reduce the maintenance load.

Hope this helps...

[waterfall larry]

Ax man
be careful about putting liner where water can get under it. Water under the liner can cause the liner to rise or float up. Putting rocks on top of the liner can help prevent the liner from floating up but only where there are rocks. If sub surface water causes the liner to rise or float up in between the rocks, this will stretch the liner, which could lead to premature liner failure.

Stone henge
you brought up the problem with skinners and their going dry if the water level goes below the opening in the skimmer box. This will certainly kill the pump, which isn’t good.
However there are 3 solutions.
One an external pump
Two a water auto fill device / system
Three a mercury switch electric cut off float switch.
In my book number 3 is the best solution. Little Giant makes a nice one.

Trees,
you seem to have it down pat with bog filters. One of my objections to bog filters is cost. The reason why I am a bit anal about cost is that I think that one of the traits of the absolutely best waterfall and pond possible, is the cost or low cost. Keeping cost down without sacrificing any thing valuable and beneficial lets me sell more waterfalls and ponds and eliminate competition. With this in mind, what are your thoughts on the cost of bog filters?
- Is the cost worth it?
- Can a pond be maintained clean enough without a bog filter and just an effective skimmer?
- What is the absolute smallest you would go on a bog filter?
- With cost in mind, is there a less expensive alternative to a bog filter?
- You mentioned several things that a bog filter does. Can these goals or benefits be achieved with other means, that might be less expensive. Would Barley bales and algae killing chemicals be less expensive ways to get the benefits of a bog filter?
- if all of the benefits of a bog filter could be achieved by other means and if these other means were less expensive, wouldn’t that make a bog filter not the best thing to do?

Personally I like bog areas and feel that they add a really awesome touch to a plain jane old pond. I am also partial to sandy beaches. The reason why I like sandy beaches and bog areas is that they are another way to deal with the aesthetics of a natural looking shoreline. I hate the pearl necklace look of non stop, all touching each other, line of rocks.
Therefore, would this be possible in your opinion. Most of the bog areas I have seen have been to one side or the other of the pond. Instead of the bog area being to one side of the pond, could the bog area be a 7 foot or so wide area that extends around the perimeter of the pond? Do you understand what I am suggesting?

[Ax Man]

Now we are getting some where!
I belive you are suggesting a real bog with no pump, which I think would work. But in this application I feel the bog as I discribed it ( and thanks trees for your follow up) is going to be the better way to fuel my stream and use up the excess nitrates. This is a 20 plus year old pond, which had plants natural style, turtles,frogs and all such small critters.
Then The local apps guy came in and nuked all of the plants.
I was hoping he had a plan other than making a grand off of my client.
So now it's my turn. I'll give the plants a couple places to be, stream and waterfalls for the kids and parents to enjoy and cleaner water for the critters.

I worry that if we run into drought and the water drops a foot, then the skimmer won't be working, hence my try for a combination of duties for the bog.
And as Trees suggests, I'll be there for a reasonable amount of maintenance.

[Ston Wurks]

Back in the day, before boxes. I built all ponds with a bog above them to filter water and mass plants to mimic natural surroundings-they worked very well. So well, I still build bogs above ponds whenever possible.

Even with skimmers in use today, no need for "upflow filter" if there is the room for the bog area. And, besides a well-planted bog is a great aesthetic accent for any waterfeature.