I thought I knew what I was doing!

[Mark in Poole]

I am just trying to do my homework before I start building my pond. The pond will be 12 x 8 x 4ft, I want to go from bottom drain to skimmer to bog filter to mechanical filter.

I have attached an absolutely outstanding diagram which might help build a picture but will certainly create some confusion. And the odd giggle!!

I want to also use a uv filter.

I don't have a clue what pump/ filter etc to use and I'm not even sure where they would go and how they would be connected.

If there is anyone out there who I haven't confused too much and who is not laughing too much to reply I would love some help?

 

[addy1]

Welcome to our group of friendly ponders.
They love to help!

I have no bottom drain no skimmer pump just a big bog to filter the water.

 

[Mark in Poole]

Thank you addy

 

[Lisak1]

OK. There's no reason for your bottom drain to go to the skimmer - typically the bottom drain goes direct to the filter. The skimmer exists to pull water off the surface of the pond toward the pump - thereby skimming any debris off the top before it can sink. So... I'm not exactly sure where your pump is in this scenario (you are planning to have a pump, right?) but it should be either in the pond itself, in the skimmer or you can have an external pump.

Moving on, when people use a "bog" filtration, it generally feeds directly back into the pond - no need to put it through mechanical filtration because the bog filter is there to pull nutrients from the water. The invisible stuff that creates problems but you can't really see it. So mechanical filtration needs to come BEFORE the bog, not after.

Let me study some more...

 

[Mark in Poole]

Hi Lisa, The pump is really my biggest issue as I don't know where it would go. Clearly it would go before the bog filter then gravity back through the waterfall by gravity.

I am lost by adding a mechanical filter. I have read that it can't go before the bog filter because it will remove the nutrients the bog needs?

As I want to keep some Koi in the pond I don't think the bog filter will be enough. Or am I wrong?

Does a skimmer have it's own pump or is it connected to the same one as the bottom drain?

 

[Lisak1]

No. You need mechanical filtration before the bog, or you will clog it up. The water that enters your bog should be free of any kind of organic matter. Some people will add a leaf basket to the plumbing prior to the bog input.

I won't answer your question specifically about whether you need filtration, except to say I have koi in my pond and my only filtration is a "bog" and a skimmer of sorts. The rest is really a matter of a lot of small details - size of pond, number of fish, etc.

A skimmer doesn't HAVE a pump - the skimmer would HOUSE the pump. You don't have to have a skimmer either actually, but most people would tell you it's helpful for keeping the surface debris out of the pond.

As for the pump - again choices are: in the pond, in the skimmer, or external. There really aren't more options that that as far as I know. The bottom drain adds an element I can't speak to - I know how they work, but I don't have one. Others here can be more helpful with that issue.

 

[Mark in Poole]

Thanks again Lisa that is very helpful. There is just only thing I don't understand. If you don't need a mechanical filter with a bog filter why will it clog up if I put one in after it?

Sorry I might take a while to understand it all.

If the filter does go first then that all seems pretty simple although I'm not quite sure what I am achieving by having both?

 

[Meyer Jordan]

Generally a settling chamber is place between the bottom drain and the pump. This allows the suspended solids to "settle" out and be removed from the water flow. This is a type of mechanical filtration. This will still allow the dissolved nutrients to precede to any form of biologiclal filtration utilized, be it biofilter or "bog" or both.
It can be plumbed through the a skimmer, but is typically plumbed with an independent line that connects with a similar line from the skimmer by means of a 3-way valve (see photo).

The pump is located after this 3-way valve in the sequence of plumbing. This allows for use of either the skimmer or the bottom drain as conditions warrant.
You want to eliminate as much suspended solids from the water as possible prior to the water reaching the biofilter or "bog".

 

[Lisak1]

If the filter does go first then that all seems pretty simple although I'm not quite sure what I am achieving by having both?

You certainly don't need both - and in fact, the standard choice seems to be one or the other. But some people do have both, plumbed separately. A bog can be fun to grow on it's own, separate from it's function as a filter. It gives you another spot to try out some other plants... gardeners love options! And some pond owners are retrofitting bogs to existing ponds, either to add more filtration or to grow more pond plants. Some people who have koi in their ponds have a hard time growing plants - they can be rough on plants - so the bog gives them a place to add plants to their pond system.

Having said that, if you have a bog you want the water that you push into the bog to be free of any organic material that could cause clogging. The typical bog design has a series of pipes laid in a grid of some sort in the bottom of the bog, the pipes are drilled with holes for water to flow through and then covered with gravel. The water travels from the bottom to the top and then flows out, usually by means of a waterfall or tube, etc. If you pump in water that's filled with leaves or algae or other organic material, those holes will quickly become clogged, rendering your bog useless. And creating one big mess for you to clean up!

So the water entering the bog isn't "clean" - it's still got lots of good nutrients to feed your bog plants - it's just clear... if that makes sense!

 

[peter hillman]

You know the terms.... bottom drain, skimmer, bog filter!!! You kinda know what you're doing.
Take your time, we all make 'adjustments' to out ponds.

 

[DeepWater]

I've seen a lot of suggestions for 2 half sized pumps instead of 1 full sized pump. It adds redundancy, and in your case of wanting multiple filtering methods, may be more suited.

Often times bottom drains feed not into a skimmer, but into a settlement chamber. By the outstanding diagram, I can see there is a downward slope to the right of your pond, so maybe it would hold such a chamber quite nicely. The output of that could be pumped to the mechanical filter and/or UV system and then the waterfall.

The other pump would be in the skimmer. It could pump to the bog.

All of this stuff requires a lot of piping, electrical, and giant plastic components... Does that fit into your end goal?

 

[budgenator]

Ideally the bottom drain goes to a sedimentation tank, the bottom drain picks up any fish excrement, uneaten food and any other big clumpy stuff, which settles out in the sedimentation tank. A surface skimmer is always a good idea to take care of any floating debris and it also goes into the sedimentation tank. After the sedimentation tank, sometimes a mechanical filter is used to collect finer material before the water goes to the biological filter. Good Bacteria in the biological filter break down the toxic ammonia in the water to less toxic nitrite and even less toxic nitrates. From there the water needs a vegetative filter to get the nitrates out of the water. Some of us use plants in the pond to do this, some make a bog with plants in it, others drain off about 10% of the pond water each week and use it on their gardens and others do all 3.

If you skip the sediment tank and the biofilter and go straight to the bog, it'll probably work, it'll be more fidgetty and you'll do more work to keep the water clear in the long run and have to clean out the bog more often. If your DIY inclined take a look at the http://www.skippysstuff.com/biofiltr.htm skippy filter, it does all 3 in one.

 

[Mark in Poole]

Meyer – I’m not quite sure what a settling chamber is but the name kind of gives it away so I will google it and have a look.

Lisa – I think you have it spot on there and I think I will probably go with a split system. Still to be decided. The only ponds I have ever had have been inherited, very small, poorly made, and lots and lots of work. Virtually impossible to keep clean for even a short period. Hence why I want to attempt to get it right the first time round.

Peter – Thanks for your vote of confidence. I wont even start it until I have a clear plan and thanks to all you guys things are getting clearer.

Deepwater – That all sounds pretty clear. I was initially surprised at how much piping etc there would be but that’s why I have asked you lovely people! I have certainly got the picture now. Most of it anyway.

Thank you all your comments are very much appreciated.

 

[Mark in Poole]

Thank you Budgenator very thorough. I will read that again later when I can digest it all better. Top reply!

 

[Usman]

hi , welcome , good to see u plan and research before starting , nice diagram , the bog needs to be open air on top , so it cant be under water , may be i didnt get the picture ur giving water a train roller coaster ride passing thru everywhere lol jk .

i would say you will need both if u are making a heavy duty koi pond , u will need alot of bio media and filtration , its never enuf , so i would suggest have one pump for bottom drain that goes in to settlement chamber which would has some obstructions eg netting quilt or brushes which do not allow the heavier particles to be sucked by pump so it settles down and there is a valve below which is used to drain that waste and the pump sucks water from above to anywhere u want , which can go in to mechanical filter and then in to bog that falls down as waterfall .

other pump u can use in skimmer that can have its own separate system or either going in to same filter . so you will always have backup system working if one malfunctions .

you can learn filteration and botdrain plumbing here , see whole playlist before making pond , but this is dedicated koi pond , if u want u can have garden pond with shallower borders with same plumbing .

Koi Pond Construction | Pond Filter Plumbing - Part 14 - YouTube