Filter system for small garden ponds

[dz9cfg]

I am looking for a filter system for my small pond we installed in the backyard. We have one pond at 800 gallons and one pond at 300 gallons. A small stream 4 foot wide and 20 foot long connects the ponds. The stream and ponds are lined in rocks. The gutters from the house drain into the pond. At this time we have no filter installed, and a sump pump transfers water from one pond to the other. The elevation of the ponds is minimal. and flow is slow from one pond to the other. I want to install a filter system but do not know my best options. I would like an eternal inline filter if possible. Any suggestions would be appreciated.

 

[brokensword]

search the forum for 'bog' and you'll get the BEST idea for filtration, imo and many others here. Or, wait until @poconojoe drops by...

 

[j.w]

@dz9cfg

 

[Lisak1]

I think we're gonna have to get @poconojoe to change his screen name to "poconobog"!

Welcome @dz9cfg ! And I agree - you can't beat a bog for filtration, no matter the size of the pond.

 

[Mmathis]

Hello and welcome. Do you have fish in your ponds? Plants?

When you say, “eternal, inline filter,” not sure what you mean by “eternal.” Guessing you mean internal or submerged as opposed to one outside the ponds...? Wouldn’t we all love an “eternal” (forever) filter, but I think you can’t go wrong with a bog/wetlands/eco filtration system, as has already been mentioned. Are your ponds preformed (plastic shells) or are they dug out and fitted with a flexible liner?

BTW, sump pumps aren’t usually designed for continuous use, as in a pond.

Please post some pictures of your ponds and stream, and maybe after we see what the surroundings are like, we can give you better advice (and maybe talk you into a bog filter!).

 

[poconojoe]

Here I am!
Yep, bog filtration is the best!
I was inspired by addy after reading her extensive bog showcase. Addy has her bog running over 10 years without incident or maintenance. The only maintenance may be pulling roots out of the gravel. Is that eternal enough for you?

I struggled for clear water. No matter how many store bought filters and UV lights I added, my water was still solid green. It's my fishes fault! They keep multiplying and growing larger! More poop!

If you have the space, add the bog next to the upper pond. The water gets pumped from the lower pond, to the bog, then it spills into the upper pond. Or, if the smaller pond is the upper pond, you could convert it into a bog.

A bog can be as small as a window planter box or it can be huge. It all depends on the size of your pond(s). My bog is 14 ft. X 5 ft. and 12 inches of gravel. Ideally the bog surface area should be 30% of your pond surface area.

https://www.gardenpondforum.com/threads/my-add-on-bog-build.26848/

Bog building, also called upflow filter, eco filter, wetland filter

I was asked to start a thread on how to build a bog. This is my rendition on bog building 101............. Building a bog: Before you decide to build a bog, you need to know what you want its primary purpose to be. Total pond filtration bog filtration combined with another filter. If you...

www.gardenpondforum.com

 

[addy1]

Mine is around 27 feet long, around 2.5 feet deep, around 4.5 feet wide. It got that deep cause the tractor driver ie me, didn't stop digging.

It works great, I turn off for the winter, (it holds water the plants will die if it runs dry) turn back on in the spring, water is crystal clear within a few day and stays clear all summer. Minimal string algae I get a bit on the horn wort. But never a bloom of it. Works perfect.

 

[poconojoe]

It's my first winter with the bog and so far I still have it running. I'm keeping an eye on it to see if I need to turn it off.

I'm in northeastern Pennsylvania. We had a couple of cold spells so far, but not for any great lengths of time. Right now it's 18 degrees (F) and it looks like it's going to stay below the 20's for a week or so. Last night it was 13 degrees (F).

I have to keep an eye on the spot where the water returns from the bog to the pond. If that freezes over, I'll have to shut it down. I doubt it will freeze over with all that movement, but I don't want water pouring on top of a frozen surface, it might spill out of the pond. It's unlikely it will reach the shoreline since I have a deicer nearby. I also have two air stones and a small fountain.

 

[addy1]

My surface area is so large on the bog, it really effects the ponds water temperature. I don't want that much super chilled water pouring in to the pond. I have watched it drop 5-7 degrees just overnight when we are doing our hot cold bounce.

 

[poconojoe]

My surface area is so large on the bog, it really effects the ponds water temperature. I don't want that much super chilled water pouring in to the pond. I have watched it drop 5-7 degrees just overnight when we are doing our hot cold bounce.

Ah! That's a very good point! Super cool water entering the pond....not good!

The water level in my bog seems to have risen an inch or two. Maybe it didn't rise at all. Perhaps the gravel just settled. It's only 8 months old. Before the winter it just had a small stream toward the middle, but now the whole thing has about 1-2 inches of water above the gravel. Could it have happened because I removed all the tropical plants and their roots? Maybe I should try clearing out the area where it flows over to the pond. Get that area lower so as to lower the level of the whole bog.

 

[brokensword]

Ah! That's a very good point! Super cool water entering the pond....not good!

The water level in my bog seems to have risen an inch or two. Maybe it didn't rise at all. Perhaps the gravel just settled. It's only 8 months old. Before the winter it just had a small stream toward the middle, but now the whole thing has about 1-2 inches of water above the gravel. Could it have happened because I removed all the tropical plants and their roots? Maybe I should try clearing out the area where it flows over to the pond. Get that area lower so as to lower the level of the whole bog.

...and this is why PJ gets paid the big bucks...

 

[addy1]

but now the whole thing has about 1-2 inches of water above the gravel.

Over a period of about 3ish years I had to raise the edge. As the bog matured the water level raised over the pea gravel. I think I am about 4 inches higher from the first time I turned it on. I even added some gravel the second year, after that just raised the edge and did not worry about it. I do have areas with the water below the gravel, above the gravel, right at the gravel. That is all due to my grooming the bog, raking and moving the gravel around now and then.

 

[addy1]

Maybe I should try clearing out the area where it flows over to the pond. Get that area lower so as to lower the level of the whole bog.

That will work for awhile I do that off and all during the summer. Try to keep a path down the middle of the bog. I mainly yank plants that start to obstruct the flow. Mine weeps over the entire bog wall (pond side) that was supposed to be below the water level. I get a good water mix now. That is with the water fall flowing full force.

 

[poconojoe]

Over a period of about 3ish years I had to raise the edge. As the bog matured the water level raised over the pea gravel. I think I am about 4 inches higher from the first time I turned it on. I even added some gravel the second year, after that just raised the edge and did not worry about it. I do have areas with the water below the gravel, above the gravel, right at the gravel. That is all due to my grooming the bog, raking and moving the gravel around now and then.

Luckily I build the walls of the bog way too high. I have plenty of room for any rise of water level. I do have a concern about the water temperature lowering (as you mentioned) due to it being exposed (above the gravel).
If we get a warm day, I'll try and shift some gravel. I originally had just a slight stream down the middle. The water was mostly covered by gravel.

 

[addy1]

I do have a concern about the water temperature lowering (as you mentioned) due to it being exposed (above the gravel).

I started paying attention as the air temps went up and down as to what it did to the water temperature, years ago. I have a temperature probe in the water which transmits to my davis weather station. I get real time readings.
A cold night would drive the temperature right down. Mine does have a lot of surface area. A hot sunny day would bring it up. But even with full sun in the summer, heat in the 90's the pond never jumped over 85 or so. Then again mid summer the bog is FULL of plants so the water is pretty shaded, now that I think of it.