To Bog Or Not To Bog ??

[drjay9051]

Just finishing up the waterfall/stream. It was much more work than I had anticipated !

Anyway, at present I have no real filtration save the pond itself. However have only a few goldfish. I am considering adding a bog for even clearer water.

I have read many of the threads related to bog filters. In addition Nelson's Water Garden's has a nice write up on bog construction:
https://nelsonwatergardens.com/gravel-bog-filter-construction/


Seems like most advocate a depth of 12 inches. Others say go deeper. Much of the Everglades is bog and it is fore sure deeper than 12 inches ?

Some recommend water level just above gravel while some say water level just below gravel..

Most seem to advocate 3/8 pea gravel while others recommend a variety of substrate sizes.

Some say SLOW flow while others recommend rapid turnover.

I suppose we all have opinions like we all have certain parts of anatomy but any consensus here on my favorite forum?

In the end I suppose they will all work to some degree.

2 major questions if I do construct a bog:

1. I have several mesh bags full of bio balls. Any reason I cannot or should not lay them down below the gravel. They are paid for and just sitting in the garage.

2. Of greater concern I have read a couple of posts on other forums which claim a bog will for sure fail at some point. Here is a case in point:

IF you REALLY BELIEVE THIS, I have some land I'd love you to see that I'm trying to sell!lol

You guys crack me up! You're all trying to do this, that and the other thing and think or are trying to convince yourself it will work. I've been around this hobby for over 45 years and I've seen all this type of stuff before. Most all of it is gone now, because either the owner grew older and couldn't shovel sh$t anymore or all the fish died and the owners filled in the pond. What these bogs filters/gravel filters are trying to mimic is Mother Nature. Where they fall short is that they are not incorporated into an open flow system such as a natural river/stream. They are integrated into a closed system, which by it's very nature, constantly recirculates the same water over and over again. So, the nutrients continue to build/break down creating an anaerobic system. Some folks think this the inexpensive way or the more "natural" way of filtering water, but they really don't have a clue what they're talking about as they've never dealt with the system after 1-2 years and then trying to clean it.

Those snorkels and centipedes from Aquascape DO NOT allow you to clean out the mulm that collects in the gravel placed all around them. Even bioballs in bags won't come clean. The only thing you might be able to clean would be the centipede itself, but everything else around/above it will still have sediment, organics, waste stuck inside it. Even those matrix boxes are a problem. We just finished mucking one these "upper pond/gravel filters" out last Friday. It was installed 1 year ago and was the ONLY so-called filtration installed when the pond was built. Overall, the pond itself, at first glance, appears to be beautifully done. The rock work in the waterfall is really nice. I won't tell you what I think of all the rock INSIDE the pond, oh, and the "koi caves" that were built into the rocked in walls when built! What a disaster. See my previous post about mucking this filter out.

But, alas, you can lead the innocent/unsuspecting newbie around by the ring in their nose and the string attached to their wallets, but you can't keep 'em from drinking the Koolaid! BTW, loco4koi, that "pond builder" should be taken out and shot at sunset! He has no clue what a real, properly functioning pond needs to stay clean and healthy. These guys are taught by Aquascapes Designs in structured classes. The MOST IMPORTANT ITEM they are constantly being told during the seminars is, "Get in, Get out, and GET PAID"! I am quoting the EXACT words of a seminar instructor from Aquascape that my partner attending while learning how to build a pondless waterfall back in 2004! It still is being taught TODAY!

So, believe what you want, and enjoy mucking around in some rather unhealthy situations as long as you're young. You won't be doing is when your first Social Security check arrives, I'll guarantee you that!!!

Mike

WILL A BOG FAIL DOWN THE ROAD IF CLEANED OUT SAY ONCE A YEAR?

Lastly: What is the formula to calculate so called "dwell time" or should I just ignore this concept and have water flow through the bog and adjust as I see decline or improvement.

Thanks.

 

[Jhn]

You don’t want fast flow through a bog, the idea is as the water flow Slows down the sediment/mulm falls out of it. There is a formula for dwell time, I don’t know what it is and not concerned about it much. It is somewhere in one of @combatwombat’s threads.

I Wouldnt put those bioballs in a strictly peagravel bog with a pvc manifold. If you do water matrix block/centipede/snorkel bog, then you could fill the water matrix blocks with them. I know some pond contractors have been experimenting with it, but not sure how it went long term.

As for a bog failing in a year, if setup correctly it will not fail. Have had a pond and bog for over 10 years now and the original one has been doing fine. Ie the pond contractor saying these will fail, he didn’t describe how those bogs that supposedly failed, were setup. You don’t want to feed a bog without some type of mechanical filter to catch large debris, between it and the pump. Ie don’t feed it straight from a bottom drain, without a settlement tank in between. can feed it from an intake bay, or skimmer.

Many of us on here as you noticed have run many different styles of bogs successfully for years, without any back break8ng work to maintain them. To me too any time a contractor tells you that makes blanket statements, without directly looking at what is going on is just trying to make money off customers that don’t really need anything done.(speaking from being a construction contractor myself)

 

[addy1]

Mine is 2.5 feet deep just pea gravel and pvc pipes. Some water over the gravel some water below the gravel.

It has been running since 2010, never cleaned. Except yanking excess plant growth.

Turned off in the fall, fired back up in the spring. pond water stays clear.

My bog is large, it filters 10 ponds of various sizes.

I was told by many don't bother it will never work. I ignored them. It works perfectly. I would never go back to filters.

Goldfish only, no koi. Tons of frogs and other critters.

Water flow? 6800 gph pump, large bog area.

 

[JRS]

Definitely bog. I added a little one to my system which includes three turtle tubs, after seeing them mentioned on the forum and have never had green water since. Just a baby bog, about 2' x 3' and 1-2' deep, used old aquarium gravel and cattails I had, which is not normally recommended since they take over.

 

[Stephen Noble]

Seems like most advocate a depth of 12 inches. Others say go deeper. Much of the Everglades is bog and it is fore sure deeper than 12 inches ?

I must be missing this but what size is your pond?
Yes, go with a bog. The wonderful Everglades (in the dry season) with its ankle to knee deep, slow gentle flow. What a beautiful filtration system nature has given us!

 

[GBBUDD]

1. I have several mesh bags full of bio balls. Any reason I cannot or should not lay them down below the gravel. They are paid for and just sitting in the garage.
Bioballs were designed as a wet dry filter where the bio balls are stacked inside a container that is above the water line. so the water from a spray bar or drip tray slowly releases water onto the bio balls thus is just gets it wet and falls down the bio balls giving bacteria a chance to do its thing . so placing bio balls under water does have the same surface area as if it was in a trickle filter but does not have the high oxygen content to alow the bacteria to have a turbo. same principal. so will they work under water yes but not as well Bio balls have even less filtering properties as far as mechanical is concerned like next to none.
2. Of greater concern I have read a couple of posts on other forums which claim a bog will for sure fail at some point. Here is a case in point: i just tore apart a 6 year old filter that i had built and you'd hardly know it had even been used. You have to realize that there are people who go to dinner and get served their food while in a white suite. then there is the farmer who has the same meal but had to slaughter their meal . two very different life styles. Now i do believe in the bog and have botth the matrix bog snorkel and centipede as well as a smaller pvc pea stone bog . WITH BOULDERS AND GRAVEL IN THE POND OH MY..... also have a koi tunnel 5 feet long 6 feet wide . and a cave thats 6 feet deep 2.5 feet wide a foot plus tall. The key to the bog is a prefilter to collect any large sediment. This alows the otrganics in the water to to be filtered to a smaller size where it iss then pumped to the centipede thats pitched toward the snorkel. where the snorkel is a good foot deeper than the centipede and the debris is caught in this area. Now as mentioned above the key to bogs is not to throw high volume of water at the bog. The confusion comes in where people hear the wetland filter should be 30 % of the surface area of the pond. NOW THIS IS A GUIDE LINE. not you will fail if it is more or less. then there is there is the turn over the recommended is 1.5 to 2 times the ponds volume. which is true but this can be done with a skimmer and a bog also circulation jets and streams and waterfalls. my pond is 16000 gallons i push 5 to 6 k to my 20 foot long bog that is 8 feet wide and 6 feet deep with matrix blox centipede and snorkel 4 to 6 inch rock stacked aside the centipede. that levels the blocks. where the blocks are installed level then are covered with 2 to 3" river rock for about 6 to 8" and then 3/4" river rock for a good 24" and a thin layer 2to4": of pea gravel. Now i use a 12000 gph pump and like i said 5 to 6k go to my bog while the line is split and a 2" line takes water from the pump and use to just feed return jets but recently has changed as i added a 25k bead filter so that is my only mechanical filter that then feed the same return jets. So back to the bogs a toilets compared to the rectangular flat boring walls of a raised pond. to me that is cruel even my aquariums were not sterile blocks that the fish swam in. my fish on occasion get a boo boo from spawning or fighting for food of just getting spooked. So in short i say if this is failure i'll take it everyday of the week. My fish swim around vigorously, and i get at least a dozen babies every year. here it is my water temp is still in the 40's and the fish are all over the place.

 

[drjay9051]

I must be missing this but what size is your pond?
Yes, go with a bog. The wonderful Everglades (in the dry season) with its ankle to knee deep, slow gentle flow. What a beautiful filtration system nature has given us!

My pond is app. 6,000 gallons.
Waterfall/stream fed by a 5200 goh pump(actually about 3900 after head pressure calculation.

Lots of tadpoles,frogs, about 6-8 goldfish (large).
As mentioned in prior post never had alge issue and water is clear enough to see the bottom at 3 foot depth. Not swimming pool clear but my dog does not complain.

Oh yes , lots of water hyacinth and what I believe is hydrilla

 

[Hound Heaven]

As long as the dog loves it ... And in that climate you can grow anything!

I vote BOG. They can be any size, shape that you can accommodate. And they work. My pond is roughly half of yours and my bog is 4x9 feet, 1.5 foot deep and it gets a trickle of water and keeps the pond beautifully clear - KISS principle at work.

 

[GaryMoz]

My pond is app. 6,000 gallons.
Waterfall/stream fed by a 5200 goh pump(actually about 3900 after head pressure calculation.

Lots of tadpoles,frogs, about 6-8 goldfish (large).
As mentioned in prior post never had alge issue and water is clear enough to see the bottom at 3 foot depth. Not swimming pool clear but my dog does not complain.

Oh yes , lots of water hyacinth and what I believe is hydrilla

Sorry to go off at a tangent but your pond and flow rate is almost identical to the one I'm building. What size is your waterfall? I just trying to work out what size to make the spillway. I've read somewhere 100gph per inch but that would make it 50" wide, a bit on the wide side.

 

[GBBUDD]

aquascapes says 1500 gallons per foot so the numbers are close to each other

 

[drjay9051]

Sorry to go off at a tangent but your pond and flow rate is almost identical to the one I'm building. What size is your waterfall? I just trying to work out what size to make the spillway. I've read somewhere 100gph per inch but that would make it 50" wide, a bit on the wide side.

I have a 23 inch spillway. I like the flow. Fast and loud.

When I cut down flow it was just too "sedate' for my liking.


Any questions feel free to email me at (e-mail address removed)

 

[GaryMoz]

I have a 23 inch spillway. I like the flow. Fast and loud.

When I cut down flow it was just too "sedate' for my liking.


Any questions feel free to email me at (e-mail address removed)

Sound good, after doing a few calculations, that's roughly the size I was thinking of, any chance you could post a little video of it running?

Cheers

 

[drjay9051]

Sound good, after doing a few calculations, that's roughly the size I was thinking of, any chance you could post a little video of it running?

Cheers

Yeah, let me see if I get out of here this evening or tomorrow. I'll just shoot a little video for you.

 

[Mary00]

I pondered this question for several years, myself. My original pond was about 12 by 15, 3-4 ft deep. I am a middle-aged woman using only my own powers and a limited budget. I do have access to the right sized stones, but they would have to be dug up and cleaned. Finally, I just decided that for me it wasn’t worth the work, and actually what I really wanted was more pond. To make a bog is basically to make a pond and fill it with dirt, which ponds gradually fill up with anyway, in nature. So I made an upper pond, not as deep, that flows over into the original. With plants added in pots and tubs. And the flow is fast, making a little waterfall. I will work on it and alter it over time, because it is a hobby. Do what makes you happy.

 

[GBBUDD]

A bog is not filled with dirt. Not a wetland filter anyways it's river rock in a pile with upflow . The water is not fast but slow to give the plants an oputunity to do their thing.

You can use plants in pots sure but to be in anyway to a wetland filter the plants need to be in gravel no soil . This makes the plants take nutrients from the water